472 CETACEA. 



Urinary bladder. — This viscus is pyriform, 6 inches long in the male when con- 

 tracted ; its anterior wall 0*50 inch thick. In a female corresponding in dimensions to 

 the above, the bladder is not more than 3 inches long. In both, the inner surface above 

 the attachments of the ureters is densely rugose, while the area below them or trigone 

 is perfectly smooth. Where the ureters are connected to the posterior wall, the posi- 

 tion of each is marked internally by a deep pit-like puckering of the mucous lining, 

 and their orifices are about 0*75 of an inch below and internal to this. Each 

 opening is prolonged backwards and inwards for 0-9 inch as a groove ; anteriorly 

 they are separated by an interval of 0*5 inch, and below by little more than 

 0-2 inch. 



Genital organs of male. — The orifice through which the penis is protruded is 

 situated in the adult about 1 foot anterior to the anus. When retracted the 

 organ describes two curves. Tracing it backwards for 11 inches we find it bent 

 outwards and forwards upon itself for 4 inches, and then backwards and inwards 

 for 3 inches more; so that the total length of the penis when straight is fuUy 

 18 inches. It is 1'50 inch in diameter at the base of the glans and 2 inches at its 

 thickest part, immediately posterior to the second curve. The body is oval in 

 transverse section, but the base of the long filiform extremity, where it springs 

 from the bottom of the glans, presents a triangular cross section. It is interesting 

 to observe that the urethra, in the greater part of its extent, is placed to the left of 

 the mesial hue, in this following the asymmetry that characterises the uterus and the 

 cranial bones of both sexes. The filiform process (fig. 18^, p. 495) originates at the 

 base of the glans from which it is quite free. It is 5-25 inches in length and 

 projects 3 inches beyond the glans. Its free extremity is 0*20 inch in diameter, 

 while its root is one inch in thickness and is triangular in transverse section as far 

 as it lies in connection with the glans ; but beyond that point it is cylindrical and 

 whip-shaped. Its surface, on which the lobes of the glans lie, is marked by a 

 prominent longitudinal ridge which appears between the base of the lobes of the 

 glans as a triangular fold of skin of the frsenum. The under surface of the process 

 is continuous with, and on the same plane as, the neck of the penis. The 

 bilobulate glans resembles the pointed ears of a dog. The lobes are 2*25 inches in 

 length and l'^-25 in diameter at their bases, and l"-40 in their greatest breadth 

 which occurs about their middle. Their upper surface is smooth and continuous 

 with the dorsum of the neck, but their under surface is divided longitudinally into 

 three nearly equal divisions by two ridges, the more internal one corresponding 

 to the ridge of the dorsum of the filiform process to which it is applied, and the other 

 is closely opposed to its inferior lateral margin. The surface internal to the inner 

 ridge lies against the corresponding surface of the other lobe, when the organ is 

 retracted, but the lobes fall apart, when the penis is protruded. The area between 

 the two ridges is in contact with the side of the filiform body. The portion 

 external to the" outer ridge is so deeply longitudinally channelled that its free 

 margin is in contact with the ridge. This arrangement admits of the glans being 

 stored away in small compass and provides for great lateral expansion when the 



