46 



out the evidence in the sequel. The red corpuscles, then, 

 vivify the blood, and through it the animal frame, and this 

 mainly by the immediate agency of those corpuscles as 

 carriers of oxygen, received from the atmosphere in their 

 passage through the capillary vessels of the lungs, being, 

 thuS; most essential to the process of respiration and the 

 production of animal heat ; so that without these red 

 corpuscles we should be instantly suffocated, and, in short, 

 could neither move nor breathe nor have our being. 



A comparative view of the size, form, and intimate struc- 

 ture of the red corpuscles throughout the vertebrate sub- 

 kingdom was given by the aid of the illustrative diagrams. 

 The smallest red corpuscles were discovered by the lecturer 

 about twenty years since in the Musk-deer ; and the largest 

 among Mammalia in the great Anteater, the Capybara, and 

 the Whale, excepting the Elephant, in which Mandl has pre- 

 viously discovered their like largeness. Of Birds, the smal- 

 lest red corpuscles are found in the little Finches and Hum- 

 ming birds ; the largest in such big species as the Ostrich. 

 In scaly Reptiles the corpuscles are much smaller than in 

 the naked batraohians or Amphibia, and in some of these 

 last the largest red corpuscles yet known are found. In 

 Fishes the largest corpuscles occur in the Sharks and Rays ; 

 the smallest in the osseous subdivision, in which a singular 

 form, pointed at both ends, is presented in the corpuscles of 

 the Pike. As a rule, in tlie oviparous vertebrates the cor- 

 puscles are more or less oval, flattened discs, and somewhat 

 biconvex from slight projection of the nucleus ; but in the 

 Lamprey they are mostly circular ; and many of this round 

 shape, still discoid, occur among the majority of the oval 

 discs in the blood of osseous fishes, as may be seen in 

 Gasterosteus, Mugil, Belone, &c. Indeed, all the oval cor- 

 puscles, whether of the camels or oviparous vertebrates, are 

 apt to become rounded or globular from the action of inci- 

 pient putrifaction and of pure water, and retain their oval 

 shape in weak saline solutions. So, too, with the red cor- 

 puscle of mammalia, which is liable also to many variations 



