mmommpr mama?: om 2535352 . . cm. ommpqumi cm .533 ?whiz?n9in}. 13.9.4} do. I .- Hu- This pubii Issue 2 cat: a January, 1977 A Publication 0? the tended far shouid be afforded appropriate security. the use of law enforcement p?rsonne! and ?it Federal Bureau 0% Enves?gation . - osoow Hm A Practical Guide and Manual JOHN W. HICKS Special Agent Federal Bureau of Investigation FBI Laboratory - Washington, 53.0. This work is an introductory manuai to the microscopic examination and identification of hairs. information set forth herein is intended as a practicai guide to provide a foundation on which to build further knowledge and experience. - - OMCB 0? TBS mama UNITED STATES DEPARTMENT OF IUSTICE FEDERAJ.BUREAU 11.3. 20335 1 '3 .5. . This technical sugplement on ?Microscopy of Hairs" H- l; l? was written by the microscopic Analysis Unit of the Laboratory - - Branch, Scientific and Technical Services Division. Federal 1 Bureau of Investigation. It is intended for the use of the personnel of law enforcement crime laboratories. The value of preperly collected and later scientifically examined physical evidence by the crime laboratory cannot be - 2 over emphasized. It in an essential element of our criminal - 3' justice system. Each photomicrograph contained in this manual depicts 9. actual heir specimens enlarged up to 320 times and illustrates .- the subtle variations in color between specimens and within indivieuel specimens. These variations will serve as a basis ?or accurate individualization. . It is hoped the "Microscopy of Hairs? will be valuable as a guide in the crime laboratory to facilitate en? speed the examination process and further promote maximum use of physical evidence in our criminal justice system of America. Clarence M. Kelley Diractor, FBI ec? 5e ?me-?m a 9 no 3.3.x .25. eke - .4- 5% . . 4: CONTENTS Basic Structureof Hair Human Determination of Body Area and Racial Origin Comparison Other Techniques for individuaiization of Hairs Anima? Hairs - Microscopic identification. Deer Famiiy and Commercial Fur AnimateDomestic Animals . . . . . . . . . .. Report Writing and Testimony . . . . .. Siide Some Principles of Microscopy . . . . . . . Basic Parts of the Compound Microscope ..6 .24 .43 .45 .47 .50 .52 ?re-egg??th '5 i?m-v- - n-Jr t1? BASIC STRUCTURE OF HAIR A hair may be de?ned as a siender outgrowth from the of the skin of mammals, composed essentiaiiy of keratin and having three. anatomical regions: The cuticie, the cortex and the meduiia. These regions are depicted in the foiiowing diagram aiong with some of the basic structures found within those regions. Note that the cuticuiar scales aiways point from the proximal or root end ofthe hair to the distal or tip end ofthe hair (Fig. 1). It shouici be noted that the sketch beiow as wet! as others included in the text are diagrammatic in nature and are used to emphasize structural features being discussed. Certain structures may be omitted and others enhanced For purposes of illustration. A growing hair is generated from the and, with the exception ofthat point of generation, consists of dead, comi?ed ceils. Its basic constituents are keratin (a protein) and meianin (a pigment) with trace quantities of metailic eiements. These elements may be deposited in the hair during its growth or may be contaminants absorbed and adsorbed by the hair from an externai en- vironment. After a period of growth, the hair will remain in the in a ?resting? stage and will eventually be siougheci from the body. cuticie co: tex medu'lia proximal pigment granuie Figure 1 'Ifkkx .955hrk?bm?m?gflg?x m. y? a? . 1?4: 2? 1-K ac. :13? - . i {mama- -. .Es?q?w . v.31? 12.352". q: epidermis gdermis sebaceous gland . sub ?cutaneous tissue Figure 2 The hair consists of a shaft which projects above the skin and a root which is imbeddcd in the skin. The lower end ofthc root expands to form the root bulb (Fig. 2). The cuticie consists of a iayer of scales covering the hair shaft. There are three basic scaic structures (although there may be many more combinations and modi?cations of these: structures) and these are: 1. Coronal or crowmlikc. These are. characteristic of hairs of very ?ne diameter and resemble a stack ofpapcr cups (Fig. 3). Coronal scaies are commoniy encountered in the hairs ofsmali rodents and bats and only rarely in human hairs. Figure 3 -. 5 . an?. 04 . "you. Hour? -i - ?m ?"4339; -. t. .9 . offer .- l. 2. Spinous or petal~llke. These are more or less triangulanshaped scales which frequently protrude from the hair shaft (Fig. 43? Spinous scales may be found on the proximal end of mink hairs, on the fur hairs of seals, cats and certain other animals. They are never found in human hairs. Figure 4 3. Imbricate or flattened. These are overlapping scales with narrow margins and are found on the hairs of humans and otherxanir?nals (Fig. 5). .. Figure 5 The medulla is a central core of cells which may or may not be present in the hair. It may be air-filled and, ifso?, will appear as a black or opaque struc? ture under transmitted light or a white structure under reflected light. It may also be ?lled with mounting medium or some other clear substance in which case the structure may appear clear or translucent in transmitted light and nearly invisible in reflected light. If the medulla is present, its structure may be described as fragmentary (or trace). (2) discontinuous (or broken), or (3) continuous throughout the hair shaft. fragmentary discontinuous continuous WW ?Hr?1y? Figure 6 In human hairs the medulla is generally amorphous in appearance whereas in hairs from lower animals its structure is frequently very regular and well- de?ned. These medulla types may be defined as: 1. uniserial or multiserial ladder (both types found in rabbit hairs} .. . uniseria! DU muitiseriai DOUG fodder 0000 E3000 DU c300 vacuolatod iattioo amorphous Figure 7 2. celluiar or vacuoiated (commoo in hairs of many animais) 3. iattiee (deer famiiy hairs). The cortex is the main body of the hair and is composed of eiongated and fusiform (spindie-shaped) coils. The cortex may contain air spaces calico tiea! fusi, pigment grannies, and iarge maxi-shaped structures referred to as ovoid bodies. Cortica! fusi (Fig. 9) are irregular-shaped, air spaces of varying shapes and sizes. They are normally {oun? near the root ofmazure human hairs and their presence may persist throughout the hair shaft. Pigment granuies are sma?, dark, soiid structures which are granular in ap- pearance and eonsiderabiy smaiier than cortical fusi: They may vary in eoior, size, and distribution within a single hair and among animai species. Ovoid structures (Fig. 8) are iarge (much larger than pigment granules)? so?d bodies which are sphericai to ovai in shape with very regular mail-gins. They may be encountered in abundance in some cattie hairs and seer; sionaliy in human hairs from certain individuals. nxm?mv hm: nmmI mmuw?ou . n, - in)- ?L?nu- Camwmw 3m: wn?mimmnon Ego . . . . mama r. . bestow .. h. A ?lu so on HUMAN m- INTRODUCTION Human hairs may be distinguished from hairs ofother mammals in several respects. Hairs of lower animals may be classi?ed into three basic types: (1) the guard or ?beard? hairs which provide protection (2) the for or ?wool? hairs which provide insulation and (3) the tactile hairs or whiskers which pro- vide for sense enhancement. The hair covering of humans is not so differenti- ated and might be described as a modified combination of the characteristics of guard hairs and fur hairs. - Human hairs are generally consistent in color and pigmentation throughout the length of the hair shaft whereas hairs oflower animals may ex~ hibit radical color changes within a short distance (banding). Across the hair shaft, the pigmentation in human hairs is evenly distributed or more dense towards the cuticle whereas in hairs of lower animals, the pigmentation is centrally distributed (more dense toward the medulla). The medulla when present in human hairs is amorphous in its structure and its width is generally less than one third the overall diameter of the hair shaft. The medulla in hairs of lower animals is normally continuous and very regularly structured and generally occupies an area ofgrcater than one third the overall diameter of the hair shaft. There are other differences such as in the size and shape of the root struc- tures, the scale patterns and the con?guration of the hair shaft itself which serve to distinguish human hairs from other animal hairs. There are a number of possible determinations which may be made from a microscopic examination of hair. A human hair may be classi?ed according to its racial characteristics as being of Caucasian, Negroid, or Mongoloid origin. In some instances, the racial characteristics exhibited by the hair specimen may not be clearly defined indicating the source of the particular hair may be of mixed racial origin. The region of the body from which a hair came can be determined with considerable accuracy from its gross appearance and microscopic charac- teristics. Other determinations include: whether the hair was forcibly removed; irr- dications of damage such as being burned or crushed; and signs of artificial treatment such as dyeing or bleaching. The age or sex ofan individual cannot be determined with certainty from a microscopic examination of hair. The hair specimen may be compared with hairs from a known source in consideration ofa number ofvariations in structure which may occur. It is es- 6 ?55: ".3593 -. J-J *isentiai that a comparison microscope be utilized for this stage ofthe examina- tion so that the Specimens may be compared on a direct, side-by-side basis. The variations or characteristics enable an experienced examiner to dis~ tinguish between hairs from different individuals. Based on this comparison, the examiner may conciude that the hairs are consistent or similar and could have come from the same source, (2) that the hairs are dissimilar and did not come from the sarne source or that the hairs possess characteristics which are not suf?cientiy defined to arrive at a meaningful conciusion. I These rcsuits and conclusions are signi?cant in many applications. Hairs . . . . may be the oniy avaiiablc means of identi?cation in unidenti?ed deceased - cases. Hairs from the windshield on the driver's side may identify the operator 1 . '1 of a stolen vehicie which has crashed when occupants of the vehicle accuse i i one another. Hairs found on the rape victim?s clothing which match the suspect?s hair serve to corroborate her statements when the suspect denies any contact. In questions of consent in rape cases, the presence of hairs like the i victim?s which have been forcibiy removed suggests force was invoived. Hairs like the victim?s found on a hammer or club near the crime scene i may serve to identify that instrument as the murder weapon. in some in- . stances, hair may provide investigative lead vaiue such as when hairs of'a para ticuiar race, color and length are found in a ski mask discarded by a ?eeing ?5 robber. These are just a Few of the ways in which the resuits?oi? hair examinations and comparisons, even though not a positive means ofpersonai identi?cation, may be of value to the successful investigation and subsequent prosecution of a crime. DETERMINATION OF BODY AREA AND RACIAL ORIGIN The foilowing outiine sets forth certain key characteristics which serve as indicators of raciai origin (Caucasian, Negroid and Mongoloid). It shouid be understood that these indicators are generaiities and apply primarily to head hairs. The examiner of course, encounter specimens which cannot be easily associated with a particuiar racial group either clue to poorly de?ned characteristics, iimited sampic or specimen size, or inconsistent indicators. These must be identified as apparent racial mixtures or as not ciassifiabie. Even though the hair specimen may not be classi?able as to race, the speci? men may stiil be of vaiue for comparison purposes. This racial admixture may serve to further individoaiize the hair and its source, particulariy if the same mixed raciai characteristics are observed in both the questioned and known samples. mw - ?as mi run,? :23, . - DETERMINATION OF RACIAL ORIGIN Caucasian "ig. t3) 1. Shaft diameter moderate with minimal variation (mean diameter for human head hairs: 80 FL). 2. Pigment granuies sparse to moderateiy dense with fairly even distribu- tion. 3- Oval cross-sectional shape. Negroid (Fig. 14) 1. Shaft diameter moderate to fine with eonsicierabie variation. 2. Pigment granuies densier distributed (hair shaft may be opaque) and at? ranged in prominent clumps. 3. Shaft with prominent twist and curi. 4. Fiattened cross-sectional shape. Mongoinid Fig. 15) I. Shaft diameter coarse and usuaiiy with Iittie or no variation. Pigment granules densely distributed and often arranged in large patchy clumps or streaks. 3. Prominent meduiia (broad and continuous). 4. Cuticle thick. 5. Round cross~sectionai shape. The foEIowing outiine Iists Features ofindiviciuai hairs which serve to iden- tify the region of the body from which they come. Again, the features listed are generaiities and one must consider raciai origin of the specimen when analyzing features such as the degree oI?diameter variation or the meduiiary structure. Body area determinations may be made with considerable ac- curacy; however, variations may occur which make this determination difficult or impossible. These particuiar hair specimens may be oonciassi?a- bie due to immaturity or changes caused by arti?cial treatment or damage. The hairs may be ?transitional? hairs; from an area of the body between two identi?abie regions such as the sideburn, or they may simpiy be fragmem tary and not of sufficient sixe for an adequate examination. BODY AREA DETERMINATION Head hairs i. Long with moderate shaft diameter and diameter variation. . Meduiia absent to continuous and reizttiveiy narrow when compared to its structure in hairs from other body areas. . Often with cut or spiit tips. . May show arti?cial treatment,solar bieaching, or mechanical damage, such as, caused by backcombing. Soft texture (piiabie). 30 JAN (.11 many. tormstetesa-?sv ?55! ?nitely ward-'ch I . . .. . studies of frequency of occurrence due to the variations which may occur within asingle sample and the inherent dif?cuity in attempting to assign stan- dard values for degrees of variation. If, however, particuiar characteristics are seen within a hair sample which appear with regular frequency throughout the sample, then they must be considered as signi?cant for individualization purposes. The process of identi?cation or association involves distinct stages 'hrough which one must pass either consciousiy or unconsciously in the course ofan examination: ANALYSIS The individual hair specimen must be visuain separated into its compo- nent parts or characteristics. The color, size1 and configuration of these characteristics, as weli as their relationship to one another, are observed. COMPARISONS The characteristics of the questioned hair determined through analysis are compared with characteristics present in hair samples of known origin for consistencies or inconsistencies. EVALUATION Similarities or dissimilarities in the characteristics exhibited by the ques- tioned and known specimens have a certain vaiue to the examiner based on his experience in conducting similar examinations. His conclusion wili be based on his evaluation of those characteristics. HUMAN HAIR COMPARISON CHARACTERISTICS The following list is a guide to areas ofexamination which should be con? sidered in a comparison of hair specimens. The list has been organized into fifteen different features or characteristics. In the literature, one may en~ counter other lists of identifying features in hair which may enumerate 25 or more different characteristics. These other lists generaliy do not disagree in substance with the foliowing list but differ only in manner of organization. The characteristics iisted are in whole mount. RACE Those Features which serve to determine racial origin have been discussed previousiy. Again, it is pointed not that even when racial characteristics are 11 not clearly defined, it is signi?cant when these characteristics are consistent between the hair in question and the hair of known origin. BODY AREA Body area characteristics have been discussed previousiy. As a general rule, most comparisons are conducted using head hair sampies and pubic hair sampies. Hairs from some other body areas may be of limited vaiue for com~ parison purposes. COLOR There are many variations among individuals in hair color. The particuiar hue (color shade), vaiue (lightness or darkness) and intensity (saturation) of a specimen are enhanced through miemseopy so that even very subtle differences may be distinguished. LENGTH Length is considered, keeping in mind that hairs may have been out be? tween the time ofciepositof a questinned _specimen and coliection of a known . . - - p- .h 4 u. .m-mwm, .L II a: v' i net} - {Inf I H?w i a ?231: I I . 9 . "in; i it; Figure 12 Caucasian pubic hair (31324}. Note vacuoiated or medulia 72 .. Figure 13 Caucasian head hair {31390. Note Opaque and amorphous fragmentary meduila. \f?w 4mm 3 . ?x w-I? w'uu?db . i Figure 14 Negroid head ramp?4313K}. Note pigment dumps. EOE mkEmEimtmc mam: c?mmunmo m: I. . trim!"- . . . . .. .I . ..II . . . . ?$1.411. .3033 "5 Emng 3:5 3 moEcxwu .236 2c: .mmemV guano 335.1;me tum; Eowomca? m? Wig: . .5514: . . . I . -- rx?e?r?rwo- '1 Figure 1 :7 Caucasian head hairsmfonicular tag and forcibly removed with root sheath attached sampio. in addition, there may be a wide range botwcon the of the shortest and longest hairs on an individual?s soaip. Tl? The tip may be out, broken, spiit, abraded (rounded) or ?nely pointed. features may be affected by an individual?s grooming and hygiene and may even be a product of health and nutrition. ROOT Hairs are: naturain sloughod from the body poriodicaliy. The mature hair root (Fig. 16) wiI} be hardened, have a bu ibous shape and win have iittic or no foilicuiar tissue adhering to it. Pigment is sparse and absent in the mature root and there i5 froqucntiy an abundance of cortical Fusi. A root which has been plucked prior to maturation (Fig. 17) wili be soft, have a distorted appearance, and may have tissue adhering to it. Pigment is present and there are rarely cortical fusi. A root near maturity (at the hardened stage) which has been piuckcd may exhibit the buibous shape with a ?tag? ofsoft tissue attached (Fig. DIAMETER The overaii shaft diomotcr may range from very ?ne (40-50p) to very coarse (1104-12090. Consideration shouid be given to the range of variation 15 2.3.. within a particular sampic and the variation in a single hair shaft. The: of shaft diameter variation as well as the rate ofchangc between variations shouid aiso be considered. The phenomenon ofabrupt and radicai changes is referred to as buckling. CUTICLE -.s The inner margin of the cuticle may be very cieariy defined (Fig. or may be variahie and without sharp delineation. Its thickness may vary from very thick and prominent to so thin as to be indisccmibie. The cuticic coior may be very cicar or somewhat cioudy in appearaccev There may be some variation in cutick: thickness within a sample and along a singic hair shaft. SCALES A scale cast is not necessary to observe features of the scales. The scale margins are visible within the cuticle in whole mount (Fig. ?20) and their over? ail can be considered- The scates may be undisturbed and otosciy aligned with the hair shaft or may protrude outwards from the shaft. Scaie damage and protrusion are associatcci with a mechanical action such as back- combing or harsh chcmicai action such as dyeing or bleaching. The scales may protrudc out from the hair shaft and than rccurvc back to the shaft, giv? ing a looped appearancc(Fig. 3i). Figure 18 Caucasian head hairmtip razor out (1566 73w"er . ti. Figure 19 Caucasian head hair-"tip split PIGMENT The pigment granules may be absent as in ?gray? hair or may be so dense as to obscure the inner structural detail of the hair specimen. Granule size may range from very fine so that individual granules are difficult to discern to very coarse. Consideration is given to local distribution of the pigment across the hair shaft as we]! as to variatioos in distribution and density along the shaft from proximal end to distal end. The granules may be regularly arranged in streaks or clumps and the size, distribution and density of these groupings (Figs 14:) of pigment should also be considered. MEDULLA The medulla may vary From a continuous structure through the center of the hair shaft to fragmentary to absent altogether. It may be opaque or transluscent and may have a vacuolated or a completely amorphous ap- pearance. When the medulla is in its fragmentary form, the cell structures may have a fusiform or spindle-shaped appearance. The width ofthe medulla in relation to the overall shaft diameter should be considered. CBRTEX The general appearance ofthe cortex should be considered. The margins of the elongated cells comprising the cortex may be poorly de?ned or may be distinct (Fig. 20). These ceiis are prominent particuiarly in hairs which have been bleached and resuit in a strawiike appearance. ARTiricmL TREATMENT Bleaching will remove pigment from the hair and give the hair a charac? teristic yeilow cast (Fig. 22). The cortical cell margins may become more prominent and corticai fusi may develop. In addition, harsh or repeated treat? ments may make the hair shaft brittle and the scaics will appear disturbed. Arti?cai bieaching can be distinguished from solar hieaching in that a clear line ofdemarcatinn is visibie in artificiaiiy treated hairs, there is an abrupt change between untreated and treated portions. in hairs which have been bleached by the sun and nature! there is no point where change can be detected; however, a comparison of the appearance of the proximai and distal ends of the specimen reveals a hieached conditiOn. To the experienced examiner, dyed hairs possess an unnatural cast or col- or. in addition, the dye wilt be present in the cuticle as well as throughout the cortex. Keeping in mind that hair grows at the rate of about 1/2 inch per month, one may measure the distance from root to the iine ofdemarcation of the dyed portion and estimate the time sinceedy?eing. Repeated dyeing or bleaching results in several iines of demarcation at various time intervals. This would serve to make the particular Specimen unusual and unique. DAMAGE Cutting with scissors produces a sheared or squarecut appearance, whereas a razorcut (Fig. 18) is angular in appearance and very straight and clean. The length oftime since Cutting is subject to many variables and, hence, no relia? ble determination can be made. Crushed hairs (Fig. 23) exhibit a widen- ing of the hair shaft and the cortical cells may appear ruptured and separated. Broken hairs (Fig. wilt exhibit a fairly square tip with eiongated ?tags? or Fragments attached. Burned or singed hairs (Fig. 25) are charred and brittle and exhibit round vacuoles at the point of burning. CHARACTERISTICS There are other structures which may be encountered and should be con- sidered in a comparison of hair specimens. Ovoid bodies (Fig. 26) are dark, solid, ovai?shaped structures of varying sizes which are very uniform in their general appearance. When they are con; sistently present in a given hair sampie, they should be considered as 5igni?~ cant for comparison purposes. When cortical fusi (Fig. are present, their size, shape, distribution and density should be considered. 18 .. a. .umamnm.>mc2x 5 .83me an Ema; tax 35 u5 mamxm .mconumm.mmob 9t. .5 ..stob: 9.5 $02 .Qmm? km: mums mama i. .waJ. 3.211.. .1: ii .71 a. i. Emum ?Em ?me #3330 . .EmEmmu ?93ch 302 .Qm?mw ~88 Enigma n8: . . mm 33mm 4 .31 mm :mma 3m: 22m nomow 2.5an :53 333m, @353 8 wmzoims 0mm?. EmEm mm :mma 3mme macaw Np :mma 3:113" @355 . {Flufrnr?apkrurhr . . . .. . . Sam: 33 ?mumtou :mEmirms gm: mm 93mm .1 1.. ?ii 1? . r} ?me $53 296 ummx mm 2:3 33me ummn ?23260 mm 93mm Lt. Ifat . . . i. . . . .?tta??f?lu29.5fuse: .4,an vi. . ?mu. .- Figure 28 Caucasian head hair?-?ringed? or "banded" hair (44X) Certain diseases or de?ciencies may resuit in changes in the appearance of hair such as "ringed" or ?banded? hairs annuiati) (Figs. 28 and 29),,con- spicuous nodes (trichorrhexis nodosa) or reguiir diameter fluctuations '1 (monilethrix). Egg sacks ofparasitic lice (Fig. 30) may be attached to the base ofthe hair shaft. All these serve to further individualize the hair specimens. A double medulia is encountered on oceasinn (usually in beard hairs); however, uniess it is a regularly eccuring feature within a sampie, it is of littie value fur individuaiization. Figure 29 Caucasian head hair-?ringed hair (156K) 3m?cam we 2mm6a 3:Lia?mcwm mg. :mmq :mziioovma: 2sz 335 CONCLUSIONS . There are three basic conclusions which may be derived through a microscopic examination and comparison of hairs. These are: 1. That the hairs from the questioned source are consistent with the hairs in a given known sample with respect to their microscopic chat-ac teristics and, therefore, couici have come from the'source of the known sample. 2. That the hairs From the questioned source are dissimiiar'to the hairs in the given known sampie and, therefore, did not come from the source represented by the known sample, or 3. That the questioned hairs and hairs in a given known sample exhibit both similarities and unaccountable differences in their microscopic characteristics. it may be that, in the opinion of the examiner, the differences are not suf?cient to eliminate the source represented by the known sampie as being a possible source ofthe hairs in question. At the same time, the presence of these differences precludes an association being made between the questioned and known specimens. In other words, no conclusion couid be reached as to whether or not the ques~ tinned hair specimen could have come from the source represented by the known sample. Note in conclusion above, it is stated that the questioned hair ?torrid have" come From the source of the known sample. One must keep in mind that hairs are bioiogical specimens and, accordingly, subject to variation. During his anaiysis, the examiner must establish the range ofvariation within the sampie and then determine whether the questioned hair fits within that range. It has been found that when two hair sampies are randomly selected from the population and compared microscopicaiiy, it is very unuwal that they cannot be distinguished. However, the cannotbe dismissed that there may be two hair sampies whose ranges of variation overlap and, therefore, a positive identification cannot be made. OTHER TECHNIQUES FOR OF HAIRS Methods for individualization of hairs have been reported in the literature as possibie alternatives to microscopic techniques. Some methods are set forth beiow aiong with a briefdiscussion of each. NEUTRON ACTIVATION (NAM NM is an instrumental technique for trace-elements} anaiysis. It has been uscci to demonstrate the presence of some 29 elements jn hair sampies. it has. 24 been reported that if two hair specimens match in relative concentrations of eight to ten ofthesc elements, the probability that these hairs originated from a single person approaches 100%. Since these eariy reports, it has been demonstrated that hair specimens from one individuai may vary periodically in their trace elemental content according to the individuai?s diet, health, hy- giene, and environment. Accordingly, most recent scienti?c investigators agree that the results obtained from NAA are difficult, if not impossibie, to in- terpret and are u'nreiiable for purposes of'individuaiization. With additionai research, NAA may prove to be of vaiuc in this area. ABS GROUP DETERMINATION FROM HMR it has been demonstrated that antigenic substances (those substances which induce the production of antibodies) are present in tissue other than blood, inciuding keratinized tissue such as hair. The detection of these substances- providcs the basis For determining the $130 biood group. Researchers have reported some success in this tech niqu c; however, the procedure does not per? mit nitemate con?rmatory tests on singie specimens and results have been er~ ratio, especially with respect to hairs from group individuals. it is felt that the resuits of this procedure are not so fiicicritiy reiiable to be used in criminal cases. Again, further research may show some promise in this area. SCALE MEDULLARY WEEK The scaie index is de?ned by Housman (1930) as the ratio of the scale length (distance between scaie margins) to the overnli diameter of the hair shaft. it appears that this ratio is a function of shaft diameter and has been shown to be of littie vaiuc for purposes of individuaiization. The meduliary index is de?ned as the ratio ofthe width ofthe medulia to the width ofthe overaii hair shaft. Again, it appears that this index depends on overail diameter; however, there are signi?cant variations in this figure within a given sample so as to make the medullary index a meaningless Figure. SCALE COU NT The scale count, as the name implies, is the number of scale margins ob- served along a given segment of the ha?i-r?shaft. The technique described by Kirk requires that counts be taken from numerous segments along each'hair in a sample and an average of these counts? iron": ali hairs in the sample be used for statistical purposes. The arithmetic {neon of vaiucs from this tech- nique is used to demonstrate differences or similarities between specimens. However, Kirk points out that the range (if-values overlap considerabiy be? tween snmpies so that when analyzing samples of iirnited size, as in criminal cases, little significance can be attached to the scale count. 25 REFRACTIVE The refractive index of the hair cuticle may be measured and values rang- ing from L545 to 1.556 have been reported (Kirk). Some differences were demonstrated by Kirk in the ranges of the mean values of the refractive in? dices between Caucasian males and Caucasian females and, hence, it was proposed this technique may be used for sex determination from hair. However, there is a considerable overlap in these ranges and results were erat~ tic when they included members of other races and various age groups, Accordingly, the determination of refractive index For hair individualiza~ tion purposes is not suf?cientivreliable for use in criminal cases. SEX DETERMENATIGN FROM Articies have appeared in the literature concorning sex determination from hairs. Dr. Ceciljacobsen, George Washington University Medical School, has stated that sex can only be determined from tissue at the root of the hair. Further, the tissue to be examined must be immediately fixed in an ether- alcohol solutionupon plucking to insure accurate results. This requirement makes this determination impracticable in Criminal cases for obvious reasons. ION MASS ANALYSIS iOn Microprobe Mass Analysis is another technique for determination of trace elemental content. it has the same shortcomings as Neutron Activation Analysis with respect to the interprezation of data derived from the analysis. CROSS SECTIONS As a training aid, cross Sections of hairs may be of value in demonstrating the cross-sectional shape of the specimen. However, with experience, the ex? .aminer is able to approximate the cross-sectional appearance ofa hair by ob? servation ofthe specimen in whole mount (Fig. 21). Determinations such as cuticle thickness, pigment distribution and medullary structure are readily made without resorting to cross-sectioning of the hair. ELECTRON Scanning Electron ?Microscopy utilizes a beam of electrons rather than light to magnify the image ofa specimen. it is used to examine surface detail and is capable of magnifications up to 40,000 times. It is felt by most workers in this field that magni?catioris beyond 600 times for purposes of in? dividualization yield little or no information of value. Wildman (1961} makes the foliowing statement which seems in a discussion of other techniques for the examination of hairs; . .contrary to the suggestions made in some pubiications, no measure~ men: method, such for example the measurement of distance between sue? cessive external scaie margins or the measurement of fiber diameter, will it~ sci? reveai the precise origin of a fiber. . . .chemicaE tests do not distinguish between animal fibers, since ail animai ?bers consist of the same substance, nameiy keratin. The oniy satisfactory procedure is to use the method of microsc0py with a sound ?knowiedge of ?ber morphoZogy and careful in- terpretations of the obServations made.. . ANIMAL MICROSCOPIC The animal hairs discussed in this manuai wilt be limited to those animals most likely to be encountered in actual casework. An adequate reference coi? lection is essentiai for accurate identi?cation of questioned specimens. In most cases, specific identi?cation can only be accomplished with guard hair specimenst In some instances however, as with some commercial garment Furs, specimens can be identi?ed on the basis ofthe microscopic appearance of the for or ?down? hairs alone The animal hairs presented here can be ciassi?cd into three major groups on the basis of their microscopic appearance. These are: I. the deer Family and antelope 2. the commercial fur animals 3. the domestic animals. For individual identi?cation within these groups. deer Family and antelope hairs are distinguished on the basis of their scale patterns, commercial for animals are distinguished on the basis of their color, colorbands, scale pat? terns and medullary structure, and the domestic animals are distinguished primarily through their root structure, meduliary structure and pigmentation. Group characteristics are outiined below: Deer Famity and Antelope i. Very coarse overail diameter {approximateiy 300%). 2. Medulla composed of spherical ceiis which occupy entire hair (Fig. 33 3. 3. Diameter constant throughout most of hair. 4? ?Wineglass? shaped root (Fig. 32}. 5. Regular wave or crimp. Figure 32 "Wineglass" root-?deer hair (44x: 28 Figure 33 Lattice meduiiawdeer hair (156Xl Commerciai Fur Animals 1. Very ?ne to medium overall diameter (20% to $5031.). 2? Characteristic meduliary formations (serial or vacuoiated), 3. Wide diameter variations within single hair. 4. Hairs generally banded. Domestic Animals 1. Medium overali diameter (75 Mto 2. Medulla generain amorphous. 3. Moderate diameter variation within singie hair. 4? Hairs generally unbanded. 5. Characteristic root shapes. DEER FAMILY ANS ANTELOPE The deer famin and antelope hairs are not readiiy distinguishable on the basis of their gross appearance or microscopic appearance in whole mount. However, when scaie cast impressions are carefuin studied, certain patterns become apparent which can be used to separate the different members ofthis group. It is emphasized that these patterns are impressions perceived through generai observation of the entire hair specimen. Beer (Figs. 34 and 39); (White-tailed deer and muie deer): scaie margins are round and isodiametrie and resembie ?sh scaies. 1. 'rm'r. - . 29 Emca mm 3m: 8 mm m. 5.333: ammrimnma 0mm? Emc?m ab Omaaocimom?m 0mm" A 593 Figure 41 EIkwscale castilS?X} Caribou (Figs. 35 and 40): Scales are hexagonal and usuaily ionger than wide. Eik (Figs. 36_and 4i): Scaics are eiongatcd and ?ve? or six?sidcd. Scale margins are narrow and ends are pointed. Figure 42 Moosew?scaie cast (156X). Note targe overaii diameter. 31 . Figure 43 Antetope?acaie cast Moose (Figs. 37 and 42): Scales are relatively large and irregular polygons. Overall hair diameter is considerably larger than other members of this grouP. Antelope Figs. 38 and 43): . . Scales are diamond-shaped and frequently give impreesion of being ar? ranged in diagonal rows. Note that goat hairs exhibit similarities to deer Family hairs in general form (meduliary structure). However, goat hairs are generally ?ner in overall diameter (approximately 220]?) and will exhibit a narrow, pigmented cortex. No cortex is apparent in deer family hairs (cortex is only occasionally visible in elk hairs}. The scale pattern ofgoat hairs shows flattened scaic margins and no regular pattern. FUR ANIMALS The commercial fur hairs group includes several specimens which are commonly encountered in for and which are fairly distinctive in their microscopic appearance. These are rabbit, seal, mink, muskra: and chinchilla. Ofthese, seal and chinchilla are identified on the basis of the ap- pearance oftheir ?down? or fur hairs and not by their guard hairs. This is due 32 to the fact that guard hairs are frequently plucked from seal pelts for a more pleasing appearance. Chinchilla pelts have few if any guard hairs. The remaining specimens in the commercial for hairs group are identi?a- ble largely on the basis of their characteristic colors and color banding. Rabbit: Extensively used in felted fabrics, glove linings, for trim, coats. Sheds very readily. I. Medulla?. multiserial ladder (guard hairs) (Fig. 44}. 2. Ribbon-like appearance. Cross section ?attened. 3. May be various colors and Seal: Coats 1. Medulla: absent. 2. Diameter: very ?ne and uniform. 3. Scales: spinous (elongatedpetal shape) and easin visible even in whole mount (Fig. 45). 4. Pelts usually dyed and sheared {guard hairs frequently plucked). Mink: Coats, hats, stole-s, [rim 1. Characteristic shape: basal portion) of hair very fine, rapidly widening to four or ?ve times basal diameter and then reducing to a pointed tip {spear-shaped}. 2. Scales: spinous (elongated~petai shape) through ?ne basal portion of hair, changing to imbricate through ?blade? or ?shield? portion (Figs. 46 and 3. Characteristic dark brown color (other color phases possible). Maximum length: 30mm. Maximum shield diameter: 143?. Wm $333563:er 33.. ray. ?a - 58-. . .m "gm?uid ff??i?d .3. a H, .r 1.: E's; ?uh-J: in .1 (4-: Raw ?Jo-w - Figure 44 Rabbit 9m mam. $4.wa . gnu .1 l. Emma hm mn naoxw?m? man 8:33 .. ., Figure 47 cast at distai and (313K) Muskrat: Coats, trim i. Simiiar to mink in general shape and appearance. 2. Scales imbricatc throughout Fui} length. 3. Maximum icng?th; 43mm, Maximum shicid diameter: 120 g. Coats, hats, trim 1. Diameter: very fine and uniform. 2. Mcdulla?. uniseriai ladder (fur hairs) (Fig. 48). 3. Pigment usually dumped in segments between meduliary cells. 4. Very dense, even coat. Severai hairs may emanate from a singic (Fig. 49). Few, if any, guard hairs. a Raccoon (Procyan): Cpats, {rim i. Meduila: unbroken; amorphous through basal portion changing to vacuolated; broad. Banded: white: base to dark brown mig?shaft to yei1ow{orwhite)to black tip. 3. Maximum length: Mmm. Maximum diameter: 154?. Scales: diamondopetai shape (basal) to imbricate. Note: Raccoon-dog sold commercially as ?Russian rac- coon? is very simiiar in structure and appearance to Raccoon. Generaily, ?Russian raccoon? hairs are longer than raccoon. ?mam?um mm . - war-m Inh- . . - I Figure48 Figure 49 . . . bundies. - Red FOX: Stolcs, trim I. Mcdulia?. unbroken; amorphous or vacuolazcd; broad (Fig. 51), I -. Banded: brownish-gray base to ycilow (or white) to reddisbbrown tip, 3. Maximum length: i56mm. NIaximum diameter: 110p? 4: chles: vary throughout shaft. Mosaic pattern (basal) to diamond~pctal shape to c10ngatcd~petai to imbricate. Beaver: Coats. hats 1? Meduiia (fur hairs): continuous, celiuiar (beaded appearance) (Fig. 50). In guard hairs medulia is unbrok?n, ceiiu?lar and usuaily rciatively nar- row. m. .. . m. 033292 man. c5202.? an. Humxm mwim? . mg. 338: wan ma?a? new?? 2% H. 32339 833chme magmvrocmw 55:? 3mm :w 953: amwaanm? . Caymnanmw ?wmama nomnma. mania. man $qu 9.0: @3335ch . mnmwam? . ?mama? woman? .533 GutIlaf.fi.l.rt1l.1liil.l {JuluIilich-zll. mm: ?m we @005 . .. .. 3.1.. . .113114?mcqm ma - mmu man. 835. ?re-we: 3" ea DOMESTIC ANIMALS There are wide variations in coior and length of most ofthe hair specimens in this group. The identifying characteristics given are general and apply in most cases. In order to distinguish between dog and cat and between beef (cattle) and horse, it is usuaiiy necessary that the root be present. Cat . 3. Diameter: ?ne; littie variatEOn. 2. Meduiiaz unisex-i215 ladder (fur hairs) continuous; occasionally vacuo? lated in coarser hairs. 3, Seaies: spinous, very prominent. 4. May be banded. 5. Root: elongated; m3 distinct shape; ?brils frayed at base offset (Figs. 52 and 53). Bug 1. Diameter: ?ne to coarse (usually coarser than ca: hairs); diameter may vary to give short hairs a barrel-iikc appearance. . 2. Medulia: cominuous; vacuolated to amorphous; occasiona?y very?r broad. Figure 52 .am?yd-"HA Figure 53 Cat 156K) Figure 54 Dog {156x} Figure as #iguye 56 Figure 57 3. Scales: generally not prominent. -. 4. Unbandcd (pigment occasionally very coarse: and root}. 5. Root: spade-shaped (Figs. 54 and 55). Bettie 1. Diameter: coar5c. 2. Meduiia: absent or continuous; amorphous or vacuolated; width may be narrow to very broad (without mosaic pattern). I 3. Scales: imbricate and with no protrusions from hair shaft. 4. Unbandcd; ovoid structures abundant; pigment coarse. 5. - Root: efongated; met-Julian; structure continues into root area; traces of follicuiar tissue may be present {Fig 56). Horse 1. Diameter, very coarse. 2. Mcduilaz absent to unbroken; celiuiar or amorphous (mosaic pattern). 3. Scales: imbricatc; without protrusions from hair shaft. 4. Characteristic color; ?ne, evenly distribmed; no ovoid struc~ turcs. 5. Root: area adjacent to root tapers to buib-shapcd root (Fig. 39 I3 1. Diameter: coarse; uniform. 2. Mcduila: absent to centin?ous; broad. amorphous; generaily bread to very 3 Scaics: imbricatc; without protrusions from main shaft. 4. Root: not remarkable. Stiff texture, brittie; tips spiit. U1 Beat 1. Diameter: coarse. 2. Meduilai unbroken lattice; occupies nearly entire width of hair shaft. 3. Scales: imbricatc (absence nfcharacterisiic scale shapes or patierns dis~ tinguishes goat from deer family and anteiope hairs). . Figure 58 . Catt%e(156X) 40 REPORT WRITING AND TESTIMONY THE REPDRT The report simuid be clear, concise and easily understandabie. it would rareiy serve any usefui purpose to include technical terminology foreign to the iayrnan such as a detaiied description of individual characteristics. It should contain information pertinent to the requests made by the contributor of the evidence and to the examinations conducted. The evidence examined should be clearly listed and identified as to origin, either through description or con- tributor?s reference no The resuits ofthc examination shouid be set out and Followed, by a statement giving the examiner?s conciusion. It may be desirable to include a clarifying statement in which the iimiting factors ofan examination are set forth. The foiiowing is given as an exampie: Specimens: Q1 Knit cap K1 Head hair sample from suspect Resuits: Four brown head hairs were found on specimen Q1. These hairs are of Caucasian origin and have been dyed and were Found to exhibit the some microscopic characteristics as the hairs in specimen Ki. Therefore, the four brown head hairs found in the Q1 cap couici have come from the source represented by specimen Kt. It is pointed out that hairs do not possess a sufficient number of unique individuai microscopic characteristics to be positiveiy identified as having originated from a particular person to the exciusion of ail others. - Note that the statement of results {the first two sentences) sets forth fairly completely those determinations that can be made; that the hairs came from the head, that they exhibit Caucasian characteristics, that they have been dyed. and that the hairs are consistent with the K. hairs in microscopic ap? pearance. The conciusion Foiiows, then, that given these rcsuits, the hairs couid have come from the source ofthe known sampie. The last paragraph is optional and is given so that the reader may better understand the nature of the identi?cation. It may be modified in any number of ways to accuratciy describe the iimits or exciusions ofa particular conclusion. TESTIMONY Testimony ofthc expert witness shouid proceed with the same basic consti~ tuents as found in the report; namciy, the statemgm of rcsuits and the condu- sions derived from those resuhs. The witness should be prepared to discuss the process by which his rcsuits were obtained and this, of caurse. should justify the ultimate canclusion. He should endeavor to promote a better un? derstanding on the part of the court andjury into the method of his examina- tion. "rm?mw SLIDE Hair specimens are permanently mounted on glass microscope slides in a resin medium such as (Fisher Scienti?c Company), Histo-ciad (Clay-Adams Company), or Pro?Texx (Scienti?c Products Com- pany). Temporary mounts may be made using water or xyiene if desired. In most cases, hair specimens may be mounted directly after recovery; however, on occasion it may be necessary to clean debris from the hair speci- mens in order to better observe structural detail. Biood may be rinsed or soaked from the hairs with a saline solution. Care should be taken after washing to dry the hairs thoroughly as moisture droplets may result on the specimens when mounted in a medium immiscible with water. Oily or other debris~contaminated specimens may be cleansed in xylene or an ether-alcohol solution. For permanent mounts, the hair specimens are positioned on the glass siide using a few drops ofxylene to hold them in place. Excess xylene used for posi~ tinning of hair specimens should be remmed with a blotter and a few drops of the mounting medium added T?he specimen and medium are then sealed under a cover slip. With particularly stiff?textured or wirey hairs, the mounting medium itseiF may be used in piece of xyiene to position the hairs as desired. It may be necessary to weight the cover siip in order to insure a thin mount. The number of hair specimens mounted on a single slide is optionai; however, excessive overlapping should be avoided so as not to obscure obser? vation of underlying Specimens. In addition, the iimited working distance of high power objectives shouid be kept in mind. Long hairs shouid not be cut but may be arranged in a ??gure eight? pattern. Care should be taken to identify the prepared slide according to case and specimen number and initiais of the examiner. SCALE CASTS It may be necessary or desirable to makea scale cast of the hair specimen, particularly in the identi?cation of some animai hairs. A quick and easy cast may be made using a Polaroid biack and white land print coater.? A thin film is applied to a giass slide with 2 or 3 passes of the Polaroid print comer. The hair specimen is pressed onto the fiim and allowed to let stand until the Ogle. RR. BA. and Gfi'i Mitosinka. 8.5., M. Srimrar, Vol. 18, No. jan. E93. 43 lacquer hair ?/trim here Figure 59 ?lm is dry. The hair is than puilcd E'er the Him and the cast may be ob- served. Scale casts may akso be prepared using a dear lacquer such as ?ngernail polish. A ?im may be ?painted? on a glass slide or, ifthe iacquer is thinned with acetone, 21 drop may be aliowcd to run down the surface of the slide. The hair is than piaccd in the ?im and removed when the lacquer dries. Due to ?wetting? ofthe hair surface it may be necessary to trim the surface ?fths cast to remove: fragments of lacquer which obscure the cast. 44 SOME PRINCIPLES OF MICROSCOPY The: ability of a microscope to render minute detaiis as separate features (aha resolving power) depends on the numerical aperture of its objective. Tho- numcricai ?aperturc (NAJ is defined as: NA. n-Sina Where a is the angle Formed by the outermost ray of light admitted by the objective and the optical axis and is the: refractive index of the: optical medium (air, water. immersion oi!) through which this ray must pass between cover giass and from lens. objective i ens a A . 2 Slip ff x/ a A Figure 60 The resolving power (R) is measured in nanometers (I 10?9m.) and is defined as: 2 "low i 2 N.A. Where A is the wavelength of the illuminant in nanometers. The maximum useful magni?cation ofa light microscope is approximately 1000 times the: nomericai aperture of its objective. Efforts to increase the total magni?cation bayond this figure will yield no additional detaii and is re?ferred to as empty magni?cation It can be seen From Formula above that resolution may be improved by increasing the numerical aperture of the objective and/or decreasing the 45 .L z? *z-A or - N. . .. I a . was 3.1. . {n . . :5 23332:. .383 23133 Ed mwvmoa ms :5 ?323: .. 333339 Dan 8 358.83 :menmonm. ?to 333:3 m9. QQ @2223 mm obw. 2:301an mm Em: mm in 35% an. cm:an 38cm: 0: .57 . 3033: 393553. . . .. 136 mozo?msm "my? wroim :5 <3ch m9, w. Awnmowimm wo?nav mam Sax- :55: 5.1.5 won @753 55.3018; 333:3? . . >?u3i5m? . . "$9335.: . Can?? m: wnwwosav umamn no: mum: :e 0.ourIn?? . . .. 9.hquiuu . ?1.31 k. cur. (Irvin. ff BASIC PARTS OF THE COMPOUND MICROSCOPE It is important to obtain illumination ofuniform intensity over the entire ?eld of view with central of light intensity, size of illuminated ?eld of View and angular aperture. systems of illumination used in or~ dinary light microscopy are called (1) critical illumination; and (2) Kai-tier il? iumination. In critical iilumination the lamp ?lament is imaged in the plane ofthc specimcn and must be diffused through the use 053 ground glass plate. In Kohlcr iliumination, the Iamp filament is imaged in the: plane of the con- denser-diaphragm and does not require the use: of a ground glass plate to evenly illuminate the specimen field. Kohlcr illumination offers greater ver- satility in ali aspects of light microscopy. The spacimcn ?eld is illuminated with a low-voltage tungsten ?lament lamp. A blue ?lter is used in order to approximate white light. HELD DIAPHRAGM The field diaphragm protects the specimen against unnecessary heating and prevents Rare. It should be opened only as far as is necessary to clear the Fun-"7W 1\1: Figure 61 (I) illumination; (2) field diaphragm; aperture diaphragm; (4) substage condenser; stage; objective; nosepiece; headset; eyepiece. 4'7 Wan-v. fieici ofview. ifopened too Far, the excess light cause the image to iOSt: its sharpness and contrast. APERTURE DIAPHRAGM (condenser diaphragm) The aperture diaphragm determines resolution and contrast of the microscopic image provided it is smaiicr than the objective diaphragm. To observe specimens of normai contrast, stop the apertu rc diaphragm so that the objectivc aperture is reduced by approximateiy onedhird. This adjustment can be made by rcmovai of the eyepiece and observation of the apcrture diaphragm on the back ions of the objective. SUBSTAGE CONDENSER The condenser iens concentrates the iight on the object specimen. It shouici be in position with objectives having a nu mericai aperture larger than 0.25. The condenser lens may be swung out of position with objectives having an NA. of icss than 9.25. MECHANICAL STAGE The object specimen is piaced on the stage for observation. OBJECTIVE LENS The objective lens Forms an inverted and side?revcrsed intermediate image ofthe objective in the diaphragm ofthc cycpicco. The objectives desirabie for scienti?c use are ?at??cid objectives and may be classi?ed as achromats, ?uorite systems, or apochromats. The achromats are constructed of giass and are iimitcd in quality ofcorrection for color and spherical aberration. Fluorite systems are constructed of ?oorspar and offer improved coior and spherical correction over achromatic icns systems. The apochromats are complex in structure and have the highest degree of correction. Markings on the objective indicate the mechanicai tube length, the thick~ oftbe cover glass for which the objective was designed (in mm}, the mag- ni?cation ofthe intermediate image, and the numerical aperture. Markings aiso identify the system as apochromatic (Apo). ?uoritc (Fl)i or oi! immersion (Del). The absence of such characters indicates an achromatic system. 170! to? Fi 40,1035 tube length! cover siio system - magnificationfw A Figure 52 Rpm-v- . REVULVING The rcvoiving nuscpicw aitnws the convenient changing of objective The different objectivea are designed to be {mrfucnl and therefore re? quire oniy ?ne of focus (m changing. BINOCULAR TUBE 0R HEADSET The binocuiar tube aiiows {he use of both eyes in observing the object specimen. It may be adjusted according to the distance of the user. EYEPIECE 0R OCULARS The eyepiece gathers the intermediate image pruduced by the objective and magnifies the image for the observer. The product ofthe: magni?cation ofthc objective and {he magni?cation of the eyepiece yields the rcsuiting or totai magni?cation. Eyepieces may be ciassi?cd as Huyghens or compensating. cycpicces are the: simplest type while the compensating eyepieccs are more compiex and are designed to complement the: image quaiity pm- dLiccd by high power objectives. Qu?rh?'3., $1134?. . . 5?2? . i 31w a??v?n I fizi%w?f ?3 - - a r. Java? . r4' i a? GLOSSARY Achromat: Art objective iens system constructed entireiv oi'glass. Limited in quality of correction for color and spherical aberration. Apochromat: A complex objective lens system generally of wider aperture than fluorite systems. Apoehromats produce briliiant images which are cor- rected to the highest degree for coior and Spherical aberration. Chromatic Aberration: The inability ofa lens to focus light of different col- ors (or at a singie point. Coaxial: On the same axis. Color Band: A band of color on a hair which is sharply separated from adja? cent areas of different coiors above and below the band. Comparison Microscope: An instrument which consists of two separate specimen stages joined by an optical bridge. it provides for simuitaneoos side?by~side viewing of two specimens. Cortex: The primary tissue in hair which extends from the outer layer of scales (cuticle) to the central core (medulla). Cortical Fusi: Elongated or spindlechaped air spaces found in the cortex of hairs. Cuticie: The outer layer of overlapping scales which cover the hair shaft. Dispersion: The variation of the refractive index of a medium with changes in coior (or wavelength) of light. Fiuorite System: An objective lens system constructed of ?uorspar. OiTers improved color and spherical correction over achromatic lens systems. For Hairs: Fine diameter hairs which comprise the undercoat of mammais and provide for warmth. Guard Hairs: Coarse diameter hairs which provide protectiOn and are usually longer than the fur hairs. Keratin: Any of various sulphur-containing ?brous proteins that form the chemical basis For horny epidermal tissues such as hair, nails, and feathers. Meduila: The central part of certain structures such as the core oflhair. Melanin: Any ofa group of brown or black pigments occurring in plants and animals. Numerical Aperture (NA): A term which indicates the ability oft?nc objecw tive lens to make fine structurai detail in the specimen distinct. NA. 3 nuSina Oil Immersion: A technique enabling greater resoiution at higher mag~' ni?cations by introduction of a medium (oii) with higher refractive index than air between the objective aperture and specimen cover siip. 50 rm; u?a'y'ep mrzt-ulm u: 3? .. .. . Papilla: A small nippie-iikc eminence; that part of generation of the: hair from its follicle. Parfocal: An objective system of different magni?cations designed to have similar focal distances or working distances. Peripianatic: A compensating type of eyepiece d?signed for ?at and wide field Piano: An objective designed to eliminate the curvature of the image. Aiso caiied ?fiat fieid" objectives. Refractive Index: The ratio of the veiocity of light in air to its velocity in another medium. Resolving Power: The smailcst distance betwetn two points which can be seen as saparatc in the image. It is dependant on the wavelength of the il? luminant and the numerical aperture of the objective iens. NA. SpherECal Aberration: The ofa lens to converge light rays from ail points on a lens surface to a common focal point. Tactiie Hairs: Coarse, stiff hairs with specialized erectile tissue found on ail mammais except man; whiskers. Venus: Fine body hair that is present until puberty. . . .- .H. ?-mm BIBLIOGRAPHY HUMAN HAIRS Clampx. {Francis 1'1. ctiilm?. Legal Wright and Hum; Lid. Brim?. Eng- land. ?968. ?ruffed Buik?y?x Tcxtixmk (1FHismingy. The ?Willimns and Wiikcn's Company. Baltimnrc. Muryfand. [964. Cm'ncii?. 11. 15. I?usxiblc tn Identify Individuqu by Neutron :Xctivutiim Analysis of Hair? Medicine Hcicnu: and the Law. juiy. {9711 U;stde B. D., E. 8. Keeping. An Attempt all Determining Prubul??tics in Human Scan: Hair Ctunpill?isnll. liuurunl Suit:ucc.juiy, 1974, pp. 599-606. A Study (if Hairs: and Wnui. f?ub?catim} Nmniwr Two. Misr Press. Cairo. Egypt. I931. (itmmics. A. Mm?gau Vanna, Milmn and Chin?fes Umhct?gcr. Legit! Medicine I?luimingy and 'l'nxicuiugy. New Yurk, New Hams. Marsha?. Fran! Evidence lu Churics C. Timmux. Springl'icici. illitznis. 1955. Kirk. Paul L. Crime Investigulimu. Imurscicncc Publishers Inc. New York. New Yuri-L. 1953. Kirk. Paul L. Human Hu?r Stuclicx- General Cmmidcrmiunx nf Hair Individuniinuiun and in; Fm'cmic importance.jnumat of Criminal Law and V01. 5i. p. 4-36. i94n-41. . Lucy H, (iambic. Human Hair Stutlic?? Scnic Cnums. Jmu'nal uf Cz'iminui Law and Crimilmingy. Vul. 3i. p. 52?. 1941. V1.13. A. Wilmcr. Human Hair Sludicx- Refractive Index of meu Hair. jam-m1! Hr Criminaf Law and Criminology. Val. 3l. pp. ?1335!. Andre A. Ray ii. and Fred H. Inimu. Scicnli?c Evidence in Criminal Calms, The 1"uundutitm Pat-<3 inc. Mincnlu. New Ym'k. i973. Mmungua, Wi?inm and Richard A. 13315. The Biningy nl'llair Gl'nwih. Amdumic Pres?; inc. New ank. New Yuz?k. 195?. S?ilishmy. Dunuld M.. Walter B. Shanty amc! Album M. Kiigumn. W. B. Snumicm Cu. Phihldciphia. l?cnuxyivaniu. [9:35. Jurgcn. The (Tummy ni' {ht ?clut?tivc. lIm?cmuI. Ernst: and VVm-ld Inc. New Ym?k. New Ym?k, 5954. . and Science. Hurunuz't. Brunt: and Wm'ki inc. New Yurk. 1967. AmericanJurisprudence. Prmaf of Fact. pp. 569-589. Encycinpcdin Bi'illamica. Amme {If the Yurk Academy of Sciences V53. Art. 3. pp. 451-?52, March 117. 1951. ANIMAL HMRS Acimjum. A. 8., and G. E. Knicnusky. i989. A For the identi?cation of twin: of Ontario Ontm?in Dept. Land}: and Fm'cxls Res. Rem. (\Niicll.) ma. {54 pp, Appicyard. H. M. 1960. Guide In (in: ni' :lninmi ?bers. Wnui Industries Assoc. Leeds. Engiumi. pp. Brawn, F. M. 1941!. The study (11' nnumuniiam hair for muhl?upningi?ts. Prue. Am. I?hii. Sm; - Burl?cki guide: in the I-inuglmm Mil??in Cm, Human. Hull. R. and Kuhn?, K. 11.. The mnmmais 0i" North America, VI and V11. The: Press NY?Aux syn? Hardyd. and T. M. Plitt. 19%. An improved method for rcveaiingthe surface structure of fur fibers. USDI, Fish Wildi. Sew. Wildi. Cir. 7. 10 pp. Hausman. L. A. 1920. Structural characteristics of the hair of mammals. Am. Nat. . [924. Further studies of {he of the structural characteristics of mammalian hair. Am. Nat. . 1930. Recent studies of hair structure reimionships. Sci. Monxhiy 30258-2?. Kenna, C. H., and Strandine. 1945. A rapid and simpli?ed method for reveaiing the surface structure (if hair. Trans. Am. Micros. Soc. 54(2 ):53-64. Mathiak. H. A. 19383. A rapid method cro_ss~sectinning mammalian hairs.j. Wiidi. Manag. 261362-264. W. 1933i). A key to hairs of the mammais of" Southern Michigan. J. Wiidi. Manage. . 1933c. A key :0 the hairs of :he mammais of snuthern Michigan. M. 5. Thesis. Univ. Mich. Ann Arbor. 45 pp. Mayer. W. V. 1952. The hair of California mammals with keys to the dorsal guard hairs of Califmnia mammais. Am. Midi. Nat. 4893:4805?. Mnnre, Tommy 0., Liter E. Spence and Charles E. Dugneiie, 1974. identi?ealinn efthe dorsal guard hair: 0? some mammals of Wyoming. Bulietin 14. Wyoming Game and Fish Dept. Cheyenne, Wyoming. Stains, i958. Field guide to guard hairs of Middie?Westem fur harem} Wildl. Manage. 22:93-97. Wiid man. A. B. {954. The microscopy ofnnimal textile fibers. W061 Industries Research Assoc. Leeds. Engiand. 209 pp. . IBM. The identification of animal fibers. j. For. Sci. 50:. Willinmsun. V. H. H. l951. Determinatiqn of hairs by impressions} Mammal. {15. GOVERNMENT PRINTING earner. mi Cum?225420 53 f. - a?