146 THE HUMAN SPECIES 



about the size of a pea (5-9 mm. in diameter), having an excretory 

 duct with a diameter of O'5 mm. 



The Bartholini glands of the female corresponding to the 

 glands of the male are absent in the female ape, being replaced 

 by numerous cavities, which, in their turn, are absent in the 

 human female. On the other hand, the Cowperian glands are 

 larger in the apes than in man, though, compared with the 

 corresponding glands in most of the other mammals, they 

 appear smaller. Among the Carnivora they are found well 

 developed in Felis and Herpestes ; among the Insectivora, in 

 the hedgehog and mole ; all Cheiroptera ; in the ruminant and 

 non-ruminant Ungulata, and in many of the rodents. In the 

 Equidae where the glands are well developed they have from 

 six to eight ducts opening into the urethra. In the Edentata 

 but little is as yet known of them, as they have been found only 

 in the Myrmecophaga tridactyla, Chlamydophorus truncatus 

 and Dasypodida, but in the Marsupials and Monotremata they 

 are undoubtedly present and are confined to the male sex. 



The Prostate is not a specifically human organ ; indeed, it 

 occurs in almost all classes of the mammals. The only point 

 characteristic of man is that this tubular aciniform gland con- 

 tains strands of muscular fibres. The separate acini have a 

 diameter of 0*21 to 0*30 mm. In the apes the prostate is 

 always well developed, bearing no trace of having originally 

 consisted of two halves ; only in the orang, where it is longer 

 and narrower than in man, is it divided into two lobes by a 

 longitudinal sulcus. 



The bilobular construction is also peculiar to the Cheiroptera. 

 Among the Insectivora the gland is clearly of double construc- 

 tion, as shown in the mole and hedgehog ; in the non-ruminant 

 Ungulata it sometimes appears fourfold, and in the Proboscidea 

 consists of even more lobes, while in the sub-ungulata, Cetaceans, 

 ruminant Tylopoda (with the exception of the giraffe) and 

 Bovidia, as well as in the majority of the rodents, the prostate 

 forms a solid independent mass. The form varies greatly in the 

 Carnivora, the prostate of the Canidae, enclosing by means of 

 its spiral form the whole of the urethra, presenting a sharp 

 contrast to that of the Felidae and Herpestes where the dorsal 

 half of the gland is entirely absent. In the majority of the 



