EEPEODUCTIVE ELEMENTS IN MYXINE GLUTINOSA. 57 



the Scottish Marine Station, and some of these have lived there 

 for six mouths ; but they refused to feed, and probably in con- 

 sequence of this their sexual organs have not developed to the 

 mature condition. I was able to observe the normal mode of 

 life of the creatures when at rest and not seeking food. They 

 lie with their bodies entirely buried in soft mud, with the ex- 

 ception of the extreme tip of the snout, and in this condition 

 respiration is carried on by means of a current of water, which 

 enters at the nostril, passes into the pharynx, and after tra- 

 versing the gill-sacs escapes by the two branchial apertures 

 situated immediately in front of the liver. This current is 

 rendered evident by the movement of the particles of mud 

 caused on the escape of the water from the latter openings. I 

 have also obtained a large number of specimens of Myxine 

 from fishermen and by means of my own excursions, and as 1 

 failed to obtain ripe eggs or ripe spermatozoa I set myself to 

 try and elucidate the nature and development of the ova and 

 spermatozoa by the minute investigation of the immature 

 organs. 



Female Organs. — To deal with the ovaries first, careful 

 examination shows that the largest ovarian eggs are situated 

 nearest to the attached border of the mesoarium. The ovary 

 of Myxine agrees in structure and relations with that of other 

 fishes very closely ; its chief peculiarities are two in number. 

 Firstly, it is extremely thin from side to side, the edge where 

 the eggs are produced, forming a border only slightly thicker 

 than the mesoarium with which it is continuous : there is no 

 distinct boundary between ovary and mesoarium. Secondly, 

 the mesoarium is attached, not to the back of the body cavity, 

 but along the line of attachment of the mesentery with the 

 straight intestine. The eggs are produced at the free edge of 

 the ovary, which is covered by a thin epithelium ; and the eggs 

 are produced from this germinal epithelium in the same way 

 as in other Vertebrates, and are surrounded after their separa- 

 tion by a follicle consisting of a connective-tissue capsule, and 

 a follicular epithelium. I have not attempted to ascertain 

 whether tlie cells of the follicular epithelium are derived from 



