546 BIOLOGY. 



Pelvis. 



3310. In Fishes the pelvic organs, sexual parts, and 

 tail predominate. The tail, as being an appurtenance of 

 the pelvis, is larger and stronger than in other animals. 

 It mostly makes up the largest part of the body, and 

 is, properly speaking, its only motor organ. 



3311. The sexual parts have still the form of the 

 intestine, and occupy the greatest part of the abdomen. 

 The ovaria are two sacs, like two Infusoria, in whose 

 parietes granules are developed; even the testes are 

 only two such sacs or seminal vesicles wherein the " milt" 

 is contained. Fishes may be termed anorchitic, or ani- 

 mals devoid of testes. 



The ova are small,, consisting of spawn or roe without 

 shell, but they separate into albumen and vitellus. 



3312. External sexual parts are not present. Every- 

 thing usually opens into a cloaca, which is thus here a 

 true pharyngeal cavity. 



3313. With the perfected formation of the head, the 

 animal, so to speak, undergoes a sudden and entire change, 

 and the sexual parts are developed with all their accessory 

 organs, such as the sexual lung. Kidneys are present 

 and mostly an urinary bladder. The kidneys are indeed 

 still so amorphous and soft, that they more resemble 

 coagulated blood than an organ, yet meanwhile agree in 

 this respect with the 'milt ' and branchial substance. 



Abdomen. 



The abdomen is not simply confluent with the sexual 

 body, but thrust by it completely forwards. The anus 

 mostly lies in front of the middle of the body. 



3314. The intestine separates for the first time dis- 

 tinctly into cephalic and sexual, or small and large, 

 intestine. 



3315. The vitelline canal is the coecum. This is very 

 distinct in the Sharks and Rays. 



