1862. | OF THE BLOOD OF VERTEBRATES. 97 
in the corpuscles of the common goat, which had always been pre- 
viously described as the smallest known. In the sheep they are 
somewhat larger still; while in the large species of the order, as the 
Buffalo and Aurochs, the Sambur, Wapiti and Moose-deer, the cor- 
puscles are as large as in many Carnivora, and larger than in most of 
the Viverride. 
In certain Cervide, as the Mexican, Reeve’s, and the Hog Deer, 
the crescentic, lanceolate, and fusiform shapes may occur in great 
abundance, as shown in the woodcut. 
The Camelide have oval blood-corpuscles. But, as I proved in 
1839 (see foot-note, page 97) and often since, it is in shape only 
that these red corpuscles resemble those of oviparous Vertebrata. 
The corpuscles generally of the Camelide have no nucleus, and so 
agree in structure, as they do also in size, with those of their mam- 
malian allies. The oval shape of the corpuscles was discovered by 
Mandl in the Dromedary and Paco, quickly afterwards confirmed 
and found by me to exist also in the Bactrian Camel, the Llama, 
and the Vicugna. 
Rodentia.—These have large corpuscles, like those of the Qua- 
drumana. Even in that tiny creature the Harvest-mouse they are 
quite as large as in the Horse and Peccary, while in the Capybara 
they are as large as or larger than in Man. In some of the small 
active Sciuride, besides the large corpuscles, there was an unusual 
proportion of smaller ones, which might be curiously considered in 
connexion with the habits of this family. 
Edentata.—The corpuscles are large; in the Armadillo hardly 
smaller than in Man, while they are larger in the Two-toed Sloth and 
in the Great Ant-eater. The corpuscles of these two last-named ani- 
mals are the largest known among Mammalia, excepting the Elephant; 
and it may be supposed, according to the rule already explained, that 
the red corpuscles of the gigantic Glyptodon and Megatherium were 
larger than any yet seen in the class. 
Marsupiata.—The corpuscles agree in structure with those of the 
corresponding placental series of animals, and generally approach in 
size to those of the Rodentia. 
Monotremata.—The corpuscles of the Ornithorynchus are very 
like those of Man in all respects, according to the observations of 
Drs. Davy, Hobson, and Bedford ; and my examination of the blood 
of the Echidna was to the same effect. 
Red Corpuscles of Pyrenematous Vertebrates. 
Hewson’s description, when confined exclusively to these, is so 
remarkably accurate as to require little addition as regards structure. 
The regular red corpuscle of oviparous Vertebrata is a cell or vesicle 
containing a nucleus, while the regular red corpuscle of Mammalia 
has no nucleus. This is the leading or central difference, as result- 
ing entirely from my own observations, between these two great sub- 
divisions of the Vertebrata ; and thus we long since disposed of “ this 
vexed question of a nucleus.” Compare figs. 1 and 12, and the 
description of them at page 102. 
Proc. Zoou. Soc.—1862, No. VII. 
