98 PROF. GULLIVER ON THE RED CORPUSCLES [Feb. 25, 



Birds. — The vesicle, when treated with water, so far from retaining 

 its shape or becoming narrower, as erroneously represented by Pro- 

 fessor KoUiker, becomes generally more or less round in this and the 

 lower classes ; and so do the oval corpuscles of the camels. 



No bird has yet been found with the majority of the corpuscles 

 otherwise than oval. In any drop of blood a few of them may be 

 more or less circular; but their most common figure is with the 

 short diameter as 1 to the long diameter between 1^- and 2. Still 

 they vary in different species, so as to present the form of a broader 

 or narrower ellipse. The broad short shape is frequent in some 

 little granivorous and insectivorous birds, as the Rice-bird ; and 

 the narrow long shape in several birds of different orders, as the 

 Snowy Owl, Passenger Pigeon, and Butcher-bird. The thickness 

 of the corpuscle is between a third and a fourth of its short dia- 

 meter. 



As might be expected from their comparative uniformity of organi- 

 zation, in birds the size of the corpuscle is much less variable than 

 in Mammalia, and has throughout the class so far more relation to 

 the size of the species, whether of one or different orders, that Hew- 

 son would scarcely have said of this class that the corpuscles are not 

 disposed to be larger in the large than in the small species. In 

 short, no instance is yet known, cceteris paribus, of a prevalence of 

 the largest corpuscles in the small and the smallest corpuscles in the 

 large birds, taking a great number of the different-sized species to 

 compensate for aberrations ; so that the whole class resembles in this 

 respect a single order of Mammalia, and is alike without an exact or 

 regular gradation in the size of the corpuscles, the rule applying 

 only with many exceptions, as before noticed or implied. The Horn- 

 bill, for example, has larger corpuscles than some much larger birds, 

 as the Pelican. 



A very remarkable relation exists between the short diameter of 

 the oval corpuscles of birds and the diameter of the circular cor- 

 puscles of Mammalia, Indeed, so constant is this coincidence that 

 it may be accepted as a rule. I have not met with an example in 

 which the breadth of a bird's corpuscle does not closely correspond 

 to the diameter of the corpuscle of some of the Mammalia. 



Reptiles. — In structure and shape the corpuscles of reptiles are 

 the same as in birds ; but in size the reptilian corpuscles vary so 

 greatly as to afford a remarkable contrast in this respect with birds. 

 The largest occur in the naked amphibia, especially in the perenni- 

 branchiate subdivision, as discovered by Professor Wagner; and 

 the smallest in the lizards, tortoises, and serpents. Such is their 

 magnitude in the Proteus, that they may be seen with a common 

 hand-lens ; and the observation of Dr. Crisp, which accords with 

 my subsequfent examinations of them in the fresh blood, shows that 

 they are nearly as large in the great Japanese Salamander. In that 

 paradoxical creature Lepidosiren, I found that the corpuscles have the 

 true reptilian character, being larger than those yet known of any 

 fish, and having also a stronger and more durable vesicle than that 

 of the blood-corpuscle generally of fishes ; and Dr. Gray (a very 



