788 SIZE OF BLOOD-DISCS IN VARIOUS ANIMALS. 
was obtained from a slight incision in the skin of the leg, I had the 
gratification of appreciating the accuracy of Dr. Manel’s recent 
interesting discovery of the elliptical form of its blood-discs. These 
present fewer differences of size than in the rhinoceros, but among 
the elliptical particles there were a few which presented the circu- 
lar form. 
The long diameter of the average-sized elliptical discs was 
of an inch, the short diameter y^Vo- 
GIRAFFE. — The blood of this animal, — mixed arterial and 
venous, — was obtained from an incision in the integument of the 
face, and presented the particles of the circular form as in the ox 
and ordinary ruminants, and the mammiferous class generally. 
The average size of the particles was nearly one-third smaller than 
those of the human subject ; the largest (which were very few in 
number) measured the smallest of an inch ; the ave- 
rage size was _ 
This result of the examination of the blood of the largest of the 
ruminating tribe is interesting, inasmuch as it indicates that the 
size of the blood-particles relates to the condition of the whole or- 
ganization, rather than to the bulk of the species. It would appear 
from the examination of the blood-discs in the goat, sheep, and 
ox, that an unusually small size of the blood-disc was associated 
with the peculiarities of the ruminant structure. 
ARMADILLO. — The blood-discs of this little quadruped rather 
exceed in size those of the rhinoceros; but the varieties in this 
respect have a more limited range ; they present the usual mam- 
miferous form. The average diameter is -gVutftli of an English 
inch. 
The blood-discs were examined as they floated in the serum ; 
also in a portion of blood thinly spread and rapidly dried upon 
slips of glass ; lastly, as preserved in a solution of common salt, of 
the strength of ordinary serum. 
The observations were made by a Ross’s Wollaston’s doublet of 
J inch focus, with Dujardin’s illuminator, belonging to the micro- 
scope in the Royal College of Surgeons, and repeated, by the kind 
permission of Dr. Arthur Farre, with the same power and illumi- 
nator in the excellent microscope lately completed by Mr. Ross for 
that gentleman. 
Should this communication prove acceptable to your readers, I 
shall have much pleasure in communicating to you the results of 
future examinations. 
