AND THEIR FUNCTIONS. 157 



oxen is about two and a quarter pounds, and that of Asiatic 

 elephants is about seven pounds, acccording to Vet.-Capt. 

 G. H. Evans.* 



Aristotle says that most animals with blood have a 

 spleen, but, in many oviparous animals, it is so small that 

 it nearly escapes notice, especially in most birds, such as the 

 hawk, owl, kite, and pigeon, that the jEgocephalos has no 

 spleen at all, and that it is quite small in oviparous quad- 

 rupeds, such as the tortoise, lizard, crocodile, toad, and 

 frog.t He also says that the chamseleon does not appear 

 to have a spleen, t 



His statements about the absence of the spleen are not 

 satisfactory, for Rolleston says : — " A spleen is found in all 

 vertebrata in connection with the mesogastrium." § The 

 chamaeleon has a small spleen ; in one of large size I found 

 it was O'll inch long. The Mgocephalos, which was a bird, 

 would have a spleen ; this bird has not been satisfactorily 

 identified, but different writers have attempted to identify it 

 with one of the following : — godwit, long-eared owl, Scops' 

 owl, goatsucker, and snipe. 



Generally speaking, the spleen is relatively much larger 

 in mammals than in birds, reptiles, and batrachians, yet it 

 was oval and 0'68 inch long in one tawny owl, egg-shaped 

 and 0'6 inch long in a small specimen of the Grecian 

 tortoise, and it is said to be large in the crocodile. In some 

 of the other animals mentioned by Aristotle it is certainly 

 small, e.g., it was 0"2 inch long in one wall lizard, and 0'18 

 inch long in a frog. 



Aristotle was aware that the spleen was particularly 

 liable to be diseased. |1 



He gives but little information about the pancreas. He 

 merely says that a blood-vessel extends from the great 

 blood-vessel to the so-called pancreas.^ This suggests that 

 the pancreas was not generally known in his time, and 

 Aristotle seems to be the first to mention it. I cannot find 

 any reference to it in the works of Hippocrates, and the 

 information given by the ancient writers, Eufus Ephesius, 

 Galen, and others who lived after Aristotle's time, is quite 

 unimportant. 



■■'- Treatise on Elephants, Rangoon, 1901, p. 67. 

 \ H. A. ii. c. 11, s 4, + Ibid. ii. c. 7, s. 5. 



§ Forms of Animal Life, 2nd edition, 1888, p. 353. 

 II P. A. iii, c. 4, 667&. ^ H. A. iii. c. 4, s. 2. 



