Genital System of the Myxinoidea 85 



but the total amount of fluid secured from a testis seemed very small, only about two or 

 three cubic centimeters. If, as is believed by all investigators, fertilization of the eggs 

 occurs after they have been extruded from the body cavity of the female, the amount 

 of spermatic fluid seems very slight to insure bringing spermatozoa into contact with all 

 the eggs. This may account for the fact that both Dean and I, in collecting the naturally 

 deposited eggs of Bdellostoma stouti found so many unfertilized ones; Dean recovered 

 many unfertilized eggs, and I observed that only about one in every five collected was 

 fertilized. When squeezed out of the testis the fluid was milky-white, and slightly sticky. 

 The entire gonad was usually creamy-white in color. In some males the testicular follicles 

 were bulging with their contents, while in others, the testis presented a shrunken, spent 

 appearance, and yielded very little fluid when squeezed between the fingers. When these 

 latter gonads were sectioned, stained and examined under the microscope many of the 

 large folhcles were found to be empty. 



Since there are no genital ducts in either the male or female, the spermatozoa appar- 

 ently escape into the body cavity upon rupture of the follicles, and are extruded to the 

 exterior through the genital pore. I observed that males can be identified upon external 

 examination by means of a gland located on each side of the genital pore. This gland is 

 present in both males and females but is much larger in the males, and can be felt as a 

 hard lump when pressed between the thumb and forefinger. 



By consulting Table III, which has been compiled from Dean's data, the reader 

 will see that the males which he caught varied from 27 to 55 cm. in body length; the 

 ■immature males measured from 27 to 35 cm., and the mature males were 32 to 55 cm. long. 

 The average length of the mature males was 42.5 cm. I caught many males longer than 

 55 cm., measured soon after they were taken from the hook, while they were still alive; 

 the longest one was 82 cm. from tip of the nose to tip of the tail, the two points used for 

 measuring the length of the eels. The testis in this male occupied the posterior one-fourth 

 of the genital fold, was very large, and was of a creamy-white color. The follicles were 

 bulging with their contents. When examined under the microscope many of the follicles 

 were found to be filled with active spermatozoa. Sections of this testis were made later, 

 and revealed that many of the large follicles were packed with spermatozoa resembling in 

 structure those so excellently illustrated by the Schreiners (1905, 1908). These authors 

 have very thoroughly described spermatogenesis in hiyxme. I have seen no evidence to 

 lead me to believe that the formation of the spermatozoa is any different in Bdellostoma. 



All the male specimens of Bdellostoma hurgeri examined by Dean, with the single 

 exception of the young male No. 393, and all the male individuals of Bdellostoma stouti 

 examined by me, without exception, were true males, having no traces whatever of eggs 

 in the sex organ. Small, immature males, and large males with ripe spermatozoa were 

 found in great numbers. Cunningham, Nansen and the Schreiners (page 76) all reported 

 that true males were observed but rarely, and were always young and immature. In the 

 case of Bdellostoma, both Dean and I found males and females occurring in approximately 



