76 
tinguished, but it requires a very practised eye to say to 
what animal a particular globule belongs. In the accompany- 
ing figures the size and form of globules of some of the lower 
animals are given approximatively. 
The oblong forms of the globules of birds, reptiles, and 
fishes are the great distinction of the blood-globules of the 
classes below the mammalia. Size is the great distinction 
between the various groups of mammalia, but in some 
instances, as in the dog, their size approaches so near that of 
man, that it is difficult to recognise the difference. It is very 
evident that in the present state of our knowledge of this 
subject, great caution is required in giving opinions on facts 
where the lives of individuals are concerned. It is, however, 
a matter for especial regret that these subjects are not 
brought more systematically before the mind of the medical 
Fic. 16. Fie. 17. 
Blood-corpuscles, 319 diameters. 
a. Of the cow. 4. Of the pig. a. Of the dog. 46. Of the mouse. 
ce. Of the ox.  d. Of the cat. ec. Of the rabbit. d. Of the ass. 
student in his ordinary course of study. It is on the 
medical man in ordinary practice that the law, through the 
Medical Witnesses’ Act, throws the whole burden of making 
these investigations, and yet the law gives the right to men 
who have undergone no examination on these subjects to 
assume the position of witnesses on these important subjects 
in all our courts of law. 
There are many other subjects connected with our law 
courts in which the microscope is an instrument of the 
greatest importance. Thus, in the present volume Dr. Taylor 
devotes a chapter to the subject of rape. Some of the most 
important points connected with this subject can only be 
made out by the aid of the microscope. The detection of 
spermatozoa in linen and on the person can only be done 
