UROGENITAL SYSTEM 147 



ruminants, with the exception of those mentioned above, the 

 prostate is replaced by a glandular layer between the urethral 

 mucous membrane and the urethral muscle ; similarly in the 

 Marsupials and Monotremata a stratum of urethral glands 

 occupying the urethral wall supplies the place of a -prostate. 



One of the most remarkable structures in the province of 

 the urogenital system of the male human subject is the vesicula 

 prostatica, known to Morgagni and Albin, the small membranous 

 vesicle situated in the prostate and discharging at the colliculus 

 seminalis between the ejaculatory ducts ; according to Weber 

 the history of evolution proves the vesicula prostatica to be 

 a uterus masculinus. Riidinger has compared the vesicular 

 fundus with the uterus and the lower section with the cervix 

 and vagina, and is of opinion that the organ is not of so rudi- 

 mentary and unimportant a nature as is generally assumed. 



In man the ejaculatory ducts only in rare cases open into 

 the vesicula prostatica, but in the rodents where the vesicula 

 seminalis is absent this is the rule. Little study, apparently, 

 has been made of this organ in the other mammals, and 

 with regard to its presence in the anthropoids no information 

 has come to my notice. If, however, the theory of Reliquet 

 and Guepin were to be confirmed, that only the human vesicula 

 prostatica possesses follicles analogous to the alveolar depres- 

 sions of the spermatic duct and the ejaculatory duct, this would 

 indeed constitute a new specific human character. Glands in 

 communication with the wall of the spermatic duct (ductus 

 deferens) occur not only in man but in several of the classes of 

 mammals and amphibians. In man these glands take the form 

 of large cavities distributed over the wall of the spermatic duct, 

 filled with secretion and furnished with excretory ducts. These 

 glands form a distinctive character of man as contrasted with 

 the rest of the Primates, they being absent in the latter. The 

 glands of the spermatic duct constitute a distinction between 

 the otherwise nearly related Insectivora and Cheiroptera, in 

 that they are absent in the former and well developed in the 

 latter. In the ruminants they occur in varying form and are 

 absent only in certain of the Tylopoda. 



The possession of spermatic duct glands, with or without 

 ampullaceous dilation of the duct, belongs to the peculiarities 



10* 



