1889.] MICROSCOPICAL JOURNAL. 203 



from a hay-mow, striking his head upon the stick in question, thus pro- 

 ducing the injuries. Distinct spots of blood indicative of blows were 

 found on different sides of the club, and the defence, in trying to make 

 this evidence conform to their theory, raised the question of the origin 

 of these minute hairs. The testimony was to the effect that thej^ came 

 from the forehead of the deceased. This opinion was not, however, 

 based solely upon a microscopical examination of the hairs, but in con- 

 nection with other testimony previously introduced, the query being, 

 substantially, what evidence was there to show that these minute hairs 

 had any connection with the case, assuming the blood to have been from 

 deceased. 



The examination showed the hairs to have been torn out by violence, 

 inasmuch as many of them still retained the bulb and bits of lacerated 

 tissue, and the cortex more or less torn. They were found fixed upon 

 slivers of wood in locations some inches apart, and also on different 

 faces of the scantling. There being no similar hairs on any portion of 

 the scalp where the wounds occurred, except the forehead, where they 

 are plentiful, it is obvious they must have come from the latter loca- 

 tion. The hairs were embedded in groups too widely separated to con- 

 form to the theory that they were produced bv a fall or one blow, when 

 considered together with the surgical relation of the wounds. A strong 

 effort was made to throw doubt on the value of this testimony and con- 

 fuse the jury, on the ground that the hairs of some animals measured 

 the same in diameter as these referred to, and that it was, therefore, im- 

 possible to discriminate between them microscopically. On this account 

 it was claimed that the hairs might easily have been from another source, 

 the one on which the greatest stress w^as laid being the fine downy hairs 

 from a mouse. Any person familiar with the microscopical appearance 

 of hair from rodents will appreciate the absurdity of claiming a resem- 

 blance between those and the human hair in question. 



In opinion-evidence relating to hair, and the same may be said of 

 nearly all other animal tissue, the truth can often be better reached by 

 exclusion than by an attempt to designate the particular animal or per- 

 son from which it is derived. Microscopical differences between the 

 hairs of various animals are, as a rule, far easier to determine than in 

 the case of blood, the optical image being generally so characteristic as 

 to sanction, at least, the exclusion of many sources without further in- 

 vestigation. Micrometry is of little value in diagnosing a particular 

 hair, so far as its diameter is concerned, though of aid in ascertaining 

 the relative portions of medulla and cortex. 



The cortical substance of hair is constructed of large horny cells of 

 varying thickness, which requires considerable force or pressure to 

 damage. Hairs torn out by violence, especially with blunt instru- 

 ments, are frequently found indented or lacerated. The bulb is also 

 usually torn out with the shaft. The fact, however, that hair is found 

 with its bulb intact is not conclusive proof that it was removed by 

 violence, for numerous instances occur in which the hair falls out bv 

 natural process or disease. 



Of all legal problems submitted to the microscope for solution, none 

 has excited more interest, more painstaking original studv, or more 

 animated discussion than the determination and differential diagnosis 

 of blood in criminal cases. Much of the literature on the subject, writ- 



