GENEEATIVE OEGANS OF VEETEBEATA. 613 



placed in, or on tlie testes (B, t) ; tliese pass tlirougli the mesor- 

 chium to a longitudinal canal, from which canals are again given off, 

 and these pass into the so-called renal portion. The sperm, there- 

 fore, passes through a certain portion only of the kidney, and only 

 passes to the common ureter by the ducts which are given off from 

 this portion ; this ureter is developed from the secondary archi- 

 nephric duct. In proportion as this portion of the primitive kidney is 

 freed of renal secretion it is converted to the uses of the generative 

 apparatus, so that the two secretions are not commingled except in 

 the ureter. 



In the males, the Mullerian duct remains free anteriorly, 

 but it is generally closely connected with the secondary archi- 

 nephric duct. It is either complete {m), and even has a coelomic 

 ostium, or parts only are canalicular, and the rest is converted 

 into a solid chord at various points. This is most commonly the 

 case in the Auura, but in Bufo it is very well developed. In 

 the Coecilise the hinder portion has its walls provided with well- 

 developed glands, in consequence of which this portion is still 

 functional. 



In many Anura (Bufo) there is a peculiar large organ contain- 

 ing ova-like cells on the testis ; this was formerly regarded as a 

 rudimentary ovary. We do not know what function it has, any 

 more than we know that of the so-called fatty bodies which are 

 found attached to the anterior end of the germinal gland of the 

 Anura. 



Since the generative organs open into the cloaca this organ func- 

 tions as part of the generative system. In the female Urodela 

 (Salamandra) the cloacal glands take up the sperm, and function as 

 receptacula seminis. In the Coeciliae the cloaca of the male can be 

 everted, and serves as a copulatory organ. 



Semper, C, Urogenitalsystem der Selachier. — Spengel, Urogenitalsysteni der 

 Amphibien, 1, c. 



§ 453. 



The generative apparatus of the Sauropsida resembles that of 

 the Amphibia in the more important points, and has, therefore, 

 some of their arrangements more highly developed. The ovaries are 

 racemose organs, which are placed in front of, or at the sides of, the 

 vertebral column, and form large organs, which vary in size accord- 

 ing to the extent to which the eggs, which are very large in this 

 division, are developed. In the Ophidii the ovaries are placed at 

 different levels. The right one is the larger, and is generally placed 

 in front of the left one. In Birds the right ovary is atrophied. In 

 the embryo it is as large as the left one, but while the left is 

 developed it remains at a lower stage, and may at last disappear 

 completely. Rudiments of it are found in the diurnal Raptores. 



The o"viducts are again developed from the Mullerian ducts, and 

 when fully developed are large, and ordinarily coiled canals which 



