92 Bashford Dean 'Memorial Volume 



drawing in the list mentioned on page 83 by two words, "capsules retracted"; it is 

 therefore, very probable that he, too, believed that resorption is the ultimate fate of the 

 corpora lutea. Whether he thought the brown bodies in the ovaries represent either 

 atrophied eggs or corpora lutea, or both, is of course problematical. He recorded the 

 number of these brown bodies in each of six females which had corpora lutea (Table IV), 

 but left no suggestion as to what he thought they signify. In one individual (Number 5) 

 he counted 124 brown bodies; if they are atrophied corpora lutea, such a large number of 

 them would represent at least two, and possibly three, different deposits of eggs by that 

 female. If, as Dean believed probable, a female deposits eggs only once each year, female 

 Number 5 had been an adult for three and possibly four years, at the time she was caught. 



In this, Doctor Dean has furnished the only suggestion in all the literature as to the 

 normal extent of the life of a myxinoid. The time required for an embryo hagfish to 

 develop to the hatching stage is unknown, nor is the time known which elapses between 

 the hatching stage and the earliest appearance of sexual maturity. Furthermore, no one 

 has been able to gather any definite information regarding the length of time required for 

 eggs to develop to the mature condition; it may be more or less than one year. 



TIME OF SPAWNING 



Having been released from the ovary by the rupture of the ovarian follicles, the eggs 

 He free in the body cavity of the female. They are probably immediately extruded to the 

 exterior, being forced through the genital pore by contractions of the musculature in the 

 abdominal wall. No investigator has been able to observe either the act of depositing or 

 fertilizing the eggs. As Dean (1899) has suggested, since the males have no clasping or 

 ejaculatory organs, fertilization very probably occurs after the ova have been extruded 

 from the body cavity of the female. The spermatozoa enter the eggs through the micro- 

 pyle (Cunningham, 1886.2; Dean, 1899). Dean found the canal to be about the same size 

 as a spermatozoon, and therefore concluded that monospermy is the type of fertilization 

 in the Myxinoidea. 



Attempts to solve the many unknown questions concerning spawning have been 

 made by keeping the hagfish in aquaria. Ayers (1893) and Dean (1899) tried this method 

 with Bdellostoma stouti, but learned that the eels will not take food while in captivity and 

 soon die. Two pages in Dean's small notebook are filled with notes and small sketches 

 regarding movements of the eels in aquaria, and he made the following entry in regard to 

 feeding: "Food. Dead fish put in — not touched, the specimen had been kept foodless for 

 10 days. Usually die overnight. If little injured they remain for days. Even healthy lie 

 on side." Cunningham (1886.2) placed some specimens of Myxine in an aquarium, and 

 some of them lived there for six months, but they refused to feed. European investigators 

 have spent much time and money in attempts to keep Myxine alive in aquaria for observa- 

 tion; some have even constructed elaborate apparatus for experimentally duplicating 

 the temperature, pressure, and other conditions of the water in which the eels live while 



