148 THE HUMAN SPECIES 



of the Subungulata and many rodents (rabbit, beaver, true 

 Muridae and hamsters). In birds and reptiles no spermatic duct 

 glands are formed, but they abound in the amphibians. In the 

 male Anura either the caudal or oral extremity of the urethro- 

 spermatic duct expands ; during the spawning season it forms a 

 sinus of considerable size, but disappears during the winter. In 

 the Urodeles there is no sign of this ampulla in the spermatic 

 duct. 



The reproductive organs of the Vertebrates possess also 

 other special glandular vesicles serving as receptacles of semen 

 and hence called seminal vesicles. These vesicles attain full 

 development in the embryo of six months, and their occurrence 

 is not peculiar to man but common to the apes, lemurs (with 

 the exception of Cheiromys), Insectivora, ruminant and non- 

 ruminant Ungulata, Subungulata, rodents and Edentata. In 

 the birds the dilation of the posterior wall of the spermatic duct 

 before the opening into the cloaca is not of glandular construc- 

 tion but acts merely as a seminal reservoir. Of the same 

 nature is the olive-shaped expansion of the lower end of the 

 ureter, which receives the ductus deferens, in the snakes. With 

 regard to fishes, the Selache have no seminal vesicles, properly 

 speaking, but in a number of Teleosteis (gobies, blennies, 

 Cobitis, pike, etc.) Hyrtl has discovered seminal vesicles in 

 connection with the testicles. 



In conclusion, the odoriferous glands of the anal and cloacal 

 regions deserve consideration. It would seem at first sight 

 that anal glands are absent in man unless we regard as such 

 those sebaceous glands embedded in the hairy perinaeum which 

 emit a secretion with a strong odour. True anal glands are 

 absent in the apes, lemurs, ruminant and non-ruminant Ungulata, 

 Subungulata, Proboscideae, Cetaceans, Sirenia and Edentata, 

 while in the remaining classes of mammals they are sometimes 

 very well developed, especially in the Carnivora, where they 

 occur in both sexes. Further, certain of the rodents (Leporinae) 

 possess special inguinal glands varying in colour and emitting 

 a secretion which probably, like that of the anal glands, is 

 connected with the reproductive system. Of the reptiles, the 

 lizards in both sexes have small sebaceous glands situated 

 ventrally from the cloaca, the tortoises simple non-glandular 



