588 



REPTILIA. 



rently connected with the generative functions, and their excretory 

 ducts likewise open into the cloacal outlet. 



(652.) In the female Triton, as Fi s> 266. 



also in the Proteus and Siren, the 

 ovaria and oviducts offer precisely 

 the same arrangement as that met 

 with in the Frog already de- 

 scribed.* 



(653.) In the Ophidian, Chelo- 

 nian, and Saurian orders, the testes 

 of the male sex are situated in the 

 loins ; and, in fact, they occupy 

 the same position throughout the 

 oviparous Vertebrata : they offer 

 no peculiarity of structure ; only 

 differing from those of the Frog 

 in the increased length of the now 

 contorted seminal cseca of which 

 they are essentially composed. 

 From each testis a long and flexu- 

 ous vas deferens conducts the se- 

 men into the cloaca. Here, how- 

 ever, in these more elevated forms 

 of theReptilia,we have another im- 

 portant addition to the male sexual 

 apparatus ; instruments beinggiven 

 to facilitate the impregnation of 

 the female during that union of the sexes which now becomes es- 

 sential to fecundity. The earliest appearance of the copulatory 

 organ is seen in Serpents and in the Lizard tribes ; and in such rep- 

 tiles it will be observed, that the penis is rather a provision for 

 securing the juxta-position of the sexual apertures of the male and 

 female than an instrument of intromission. The two lateral halves 

 of the penis, or corpora cavernosa, as we shall have to call them 

 hereafter when they become conjoined in the mesial line, are as yet 

 quite separate, and placed at each side of the cloacal fissure, from 

 which they protrude when in a state of erection ; so that there ap- 

 pear to be two distinct organs of excitement, or, more properly 

 speaking, of prehension ; for each division, being of course im- 



* Vide Rusconi. Observations Anatomiques sur la Sirene mise en parallele avec Je 

 Protee et le tetard de la Salamandre Aquatique. A Pavie, 1837. 



