REPRODUCTIVE SYSTEM. 117 



osseous fishes, or they are arranged within chamber commu- 

 nicating by convergent seminal canal with a single tortuous 

 duct, which pursues a zigzag course, to widen at its lower 

 portion. It here receives the duct of its fellow, to finally ter- 

 minate at a point just within the cloaca. Penis small. Two 

 conspicuous organs, composed of several segments of carti- 

 lage, are placed upon opposite sides of genital pores. They 

 are termed claspers, and are employed in coition. 



Batrachia. The ovaries possess free opening into cavity 

 of abdomen at upper portion of abdominal cavity. The 

 oviduct tortuous, and in relation to the organ as in man, is 

 often of great length. In Rana (frog) the lower portions of 

 tubes dilate into a sac for temporary retention of eggs, to 

 terminate in ureter. The testicles lie upon each side of 

 spinal column upon the fore part of the kidneys. Penis 

 none in Rana; rudimentary in Proteus. 



Reptilia. The ovaries, situated in the loins, are racemose, 

 diffuse, and distinct from oviduct. The latter is, through- 

 out greater portion of length, thickened with numerous 

 follicular glandular appendages, and terminates in urethra 

 immediately in front of the urinary bladder. The testicles are 

 also in loins, and communicate with cloaca by a long flexuous 

 vas deferens. Penis in Ophidia and Sauria is divided along 

 its entire length. The two separate cavernous bodies imper- 

 forate and armed with spines. Organ prehensile as well 

 as intromittent. It is penetrated by two canals that run 

 through their long diameter from behind forwards to termin- 

 ate blindly at the glans. In Chelonia and Crocodilia the 

 cavernous bodies converge and in part unite. There is no 

 production of urethra in the organ, a groove in median line 

 serving for conduction of sperm. Spongy body absent. 

 Erection is secured by muscular action. 



Aves. The ovary of left side is, as a rule, alone devel- 

 oped. Certain birds of prey have both. Originally the or- 

 gan is flat, and marked with transverse folds. When dis- 

 tended by eggs in various degrees of development it assumes 

 a racemose appearance. Each ovum is surrounded by a 

 vascular ovisac (calyx), which, when mature, is pediculated, 



