UROGENITAL SYSTEM OF MYXINOIDS 133 



normal in both young and old females. In addition to func- 

 tional males and females, Schreiner found individuals in which 

 both testis and ovary were degenerated, and these he classed as 

 sterile animals. He also found normal females 22 cm. long and 

 less, and states that, ''lasst sich das haufige Vorkommen von 

 jungen Weibchen unmoglich mit der Annahme eines protan- 

 drischen Hermaphroditismus bei diesem Tiere vereinigen." 

 Schreiner beheves that Myxine is dioecious. 



It is well known that Bdellostoma is an animal of separate 

 sexes. The fifteen adult females examined by the writer have no 

 trace of testis lobes in any part of the mesovarium, and no 

 female elements occur in the mesorchium of any of the eight 

 adult males. The females range in length of body from 34 to 

 40 cm., and the males from 36 to 42 cm. That is to say, in this 

 particular lot of animals some of the functional males are larger 

 than the adult females, hence it is certain that Bdellostoma is 

 not a protandric hermaphi-odite. It is improbable, to say the 

 least, that of two animals so closely related as Bdellostoma and 

 Myxine, the one should have normal, separate sexes while the 

 other should possess such a pecuhar method of reproduction as 

 protandric hermaphroditism. 



Furthermore, as Dean ('99) has suggested, the occurrence of 

 large males would also discredit the theory that Myxine is a pro- 

 tandric hermaphrodite. Myxine no. 15, described above, is 

 undoubtedly a normal male, in which the only female sexual 

 products are small, completely degenerated eggs, and specimens 

 no. 12 and no. 13 are males which have become sterile with age 

 and which have no female elements whatever. Myxine no. 15 

 is 62 cm. long, no. 12 is 67 cm., and no. 13 is 63 cm. The 

 average length of the females with large eggs, from 18 to 25 mm. 

 long, is 59 cm., the longest being 64 cm. Here, then, we have 

 one normal and two sterile males which are longer than the 

 average female with large eggs. In view of these facts, it seems 

 impossible that Myxine can be a protandric hermaphrodite. 



