BLOOD-DISCS OF BIRDS AND REPTILES. 
205 
seen in the corpuscles of circulating or of freshly-drawn blood, 
as it is in that of blood which has been drawn for some little 
time; and it is best brought into view by treating the blood 
either with water or with acetic acid. The long diameter of 
the oval discs of Birds (fig. 116) varies from about 1-1700th 
to 1-2400th of an inch; and the short diameter from about 
Fig. 117.-— Blood Corpuscles of Frog. 
At a are seen the red corpuscles a, b, and the colourless corpuscle c; at b, a red 
corpuscle treated with acetic acid. 
1 -300th to 1-4800th. Thus the discs, though much longer than 
those of Man, are not in general much broader. In Reptiles, 
Fig. 118. —Blood Corpuscles of Proteus. 
o, b t red corpuscles; a*, corpuscle showing the nucleus; c, colourless corpuscle.; 
d, red corpuscle treated with water. 
