118 FOURTH REPORT — 1834. 



To the last-mentioned observers, as well as to Young, the 

 corpuscles have not appeared uniformly flattened, but con- 

 cave on their surfaces. Miiller, however, M'ho believes in 

 the existence of a central nucleus, of which he finds the 

 thickness to equal the lesser diameter of the corpuscle, has, 

 if his observations admit not of another explanation, set 

 that point at rest. 



Size. — As a rule, the size is constant in the same individual, 

 and the same species ; and their measurement assumes an 

 additional importance from the observation of Blundell, 

 and of Prevost and Dumas, that death follows the transfu- 

 sion of blood when its corpuscles differ in size from those 

 of the animal which is operated upon. 



In Man the size of the corpuscle, according to 

 Rudolphi,Sprengel,Hodgl\in, and Lister = 0"00033 in. -g-gV-o 



Kater, Prevost, and Dumas = 0'00025 toW 



WoUaston, Weber = 0-00028 ^oW 



Young = 0-00016 ^-iTTo 



If we take the mean of these, m'c find the size of the human 

 corpuscle to be ^—o^dth part of an inch in diameter. 



In different Mammalia, (Prevost and Dumas,) 

 the size of the corpuscle is the same as in 

 Man, in the Dog, Hedgehog, Swine, Rab- 

 bit, Dolphin = -00025 inch. 



Larger in Shuia Callithrix = -00030 



Smaller in Ass = -00022 



Cat = -00020 



Sheep = -00018 



Chamois = -00017 



Goat = -00014 



Hodgkin and Lister have, however, found it smaller in the 



Swine and Rabbit than in Man. 

 Diameter in Man : major axis in Frog : : 1 : 4. 

 The corpuscles are of equal magnitude in arterial and venous 



blood and similar in form. 



Stmcture. — Hewson, from observing the mode in which the 

 fresh corpuscle appears to swell in water and to change, be- 

 coming gradually colourless, and appearing as a central nu- 

 cleus surrounded by an integument, concluded that it really 

 exists in the blood in this complex form. In this opinion he 

 has been followed by Home, Edwards, Dutrochet, Prevost, 

 and Dumas. The integument has been represented as the 

 colouring matter, and the nucleus as fibrin. Raspail, how- 

 ever, gives it as the result of his observation, that when the 



