THE CIRCULATION 



103 



piled one above another, it would take at least 14,000 of 

 them to -stand an inch high. Although so small in size, 

 they are very regular in form. As seen under the micro- 

 scope, they are not globular or spherical, but flat, circular, 

 and disc-like, with central depressions on each side, some- 

 what like a pearl button that has not been perforated. In 

 freshly-drawn blood they show a disposition to arrange 

 themselves in little rolls like coins (Fig. 25). 



6. The size and shape of the blood corpuscles vary in 

 different animals, so that it is possible to discriminate be- 

 tween those of man and the lower 



animals (Fig. 26). This is a point of 

 considerable practical importance. (jP) c=> 



For example, it is sometimes desir- 

 able to decide in a court of justice <a? # 

 the source, whether from man or an 

 inferior animal, of blood stains upon 

 the clothing of an accused person, or 

 upon some deadly weapon. This may 

 be done by a microscopical examina- 

 tion of a minute/portion of the dried 

 stain, previously refreshed by means 

 of gum-water. .Certain celebrated 

 cases are recorded in which the guilt 

 of criminals has been established, and 

 they have been condemned and pun- ^pvai corpusciesof a fowl, 

 ished upon the evidence which sci- 

 ence rendered on this single point, 

 the detecting of the human from 

 other blood. 



7. The character of the blood of dead, extinct, and even 

 fossil animals, such as the mastodon, has been ascertained 

 by obtaining and examining traces of it which had been 

 shut up, perhaps for ages, in the circulatory canals of bone. 

 A means of detecting blood in minute quantities is found 



FIG. 26. 



6. The size and shape of the corpuscles ? Why is the fact important ? 



7. The character of the blood of dead animals ? Means of detecting such blood ? 



