1862.] OF THE BLOOD OF VERTEBRATES. 07 



iu 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 ai'e as large as in many Carnivora, and larger than in most of 

 the ViverridcB. 



In certain Cervidce, 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 CamelidcB 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 Camelidce have no nucleus, and so 

 agree in structure, as they do also in size, with those of tlieir 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 Sciuridce, 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 Uodentia. 



3Ionotremata. — 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 ray examination of the blood 

 of the Echidna was to the same effect. 



Red Corpuscles of PyrencEmatous 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." Corhpare figs. 1 and 12, and the 

 description of them at page 102. 



Proc. Zool. SOC.--1862, No. VII. 



