SIZE OF BLOOD-DISCS IN VARIOUS ANIMALS. 787 
The blood from the Elephant was obtained from a small vein 
on the outside of the ear. The red particles presented the usual 
figure characteristic of the mammiferous class, viz. the circular 
flattened slightly biconcave disc : their size varied more than usual, 
but that of the greatest number exceeded by about one-fourth the 
average-sized human blood-disc, which I take for the present com- 
parison at °f an English inch. The largest blood-discs of the 
elephant were twice the size of the ordinary sized human blood- 
disc; the smallest equalled them in diameter: hence the blood- 
discs of the elephant are of a large size than those of any other 
mammiferous animal hitherto examined. I need, however, hardly 
observe, that this relation of the size of the blood-particles to the 
bulk of the individual is by no means constant in the mammalia ; 
and that the discrepancy in this respect is still more remarkable 
in the lower classes. The action of the salt solution upon the 
blood-discs produced a slight diminution of their size, and the num- 
ber of those which presented the concave or basin-shaped figure 
was greater than in the recent blood. A few of the minute chyle, 
or lymph particles, were present ; but I could not distinguish in 
any of the portions of the blood examined that variety of form in 
the blood-discs which Prof. C. H. Schultze has described in the 
blood of an elephant killed at Potsdam by means of hydrocyanic 
acid, and which induces him to describe the blood of this mammi- 
ferous animal as containing in itself all the various forms of parti- 
cles which characterize respectively the blood of insects, mollusks, 
fishes, reptiles, and mammals. 
Rhinoceros. — The blood of this animal was obtained by a 
small incision in the upper lip, and was consequently of a mixed 
arterial and venous nature. The huge creature being attracted by 
a favourite dainty presented to him by his keeper, seemed quite 
insensible to the operation, and quietly allowed the blood to be col- 
lected as it trickled down. The blood-discs presented the usual 
mammiferous form, and a less variety of size than in the elephant. 
The average diameter is not greater than that of the human blood- 
disc. The largest sized blood-discs of the rhinoceros have a dia- 
meter of j sVfl of an inch : the smallest 42W 
Among the accidental circumstances observed in the examina- 
tion of the blood of the rhinoceros, I may mention that, although 
that portion spread on glass was dried under the same circum- 
stances as the rest, a far greater number of the particles presented 
the granulated or mulberry character than in the blood of the other 
quadrupeds. 
Dromedary. — In inspecting the blood of this animal, which 
* Muller’s Archiv. 1839, p. 252. 
