ECOLOGY AND BIOLOGY OF THE PACIFIC WALRUS 



39 



300r 



600r 



^ 4001- 



? 2001- 



(3) 



0 



I I I 



I I I I I I I I 



10 15 20 

 Age (years) 



25 >25 



Fig. 25. Length and weight of non-spermiogenetic testes from Pacific walruses in relation 

 to age. Each point represents the mean value of the pair from one specimen. Curves were 

 fitted visually. 



20 years. In 64 calves less than 1 month old, length of testis ranged from 60 to 

 88 mm (mean, 73 mm); weight was from 14 to 26 g (mean, 18 g). The testes of 

 23 adults 15 years old or older ranged in length from 135 to 240 mm (mean, 

 188 mm), and in weight from 150 to 584 g (mean, 394 g). During spermiogen- 

 esis, the testes of adults increase in length by about 15 % and in weight by about 

 40%. 



Os Clitoridis 



In the clitoris of the walrus, as in many other mammals (Layne 1954), there is 

 a small mass of bony tissue which is the homologue of the baculum. This bone, 

 the OS clitoridis, has not been previously described from the walrus. 



In conjunction with collection of data on reproduction in female walruses, I 

 obtained clitorides from 41 calves and 24 older animals to investigate the 

 presence and form of the bone. Upon determining by dissection that bony tissue 

 was present, I boiled each clitoris in 5 % sodium bicarbonate solution for about 



