350 FISHES 



examination of these and of numerous dead specimens showed 

 that males were always less than 2\ ft. in length : in fact the 

 largest male obtained measured only 2 ft. 2 in. A ripe specimen 

 was identified on 13th December, 1888, and was kept alive in the 

 Aquarium until 24th June, 1889, when it died, although its milt 

 was still abundant and healthy. This specimen was 18 in. long 

 and during the period mentioned it took no food. It gradually 

 deteriorated in condition ; it became thin and emaciated, and its 

 eyes became ulcerated so that it was quite blind and its skin 

 was ulcerated in several places. Several others were kept alive 

 in the ripe condition, and none of them took any food. It was 

 found that when ripe the males could be distinguished from 

 females of the same size by three peculiarities ; the propor- 

 tionately greater size and prominence of the eyes, the bluntness 

 of the snout, and the presence of pigment on the ventral surface. 



All the large conger sent to market, which vary from 3 ft. 

 to 6 ft. or 7 ft. in length, and which sometimes exceed a weight 

 of 100 lb., are therefore females. It was proved by the Ply- 

 mouth experiments that female conger in the Aquarium, 

 although they feed voraciously and grow rapidly for some time, 

 always sooner or later cease to feed, live for six months or so 

 in a fasting condition, and then die, and that such specimens 

 always contain enormously developed ovaries. There can be 

 no reasonable doubt that in the natural state conger of both sexes 

 cease to feed when the generative organs begin to mature, and 

 that they die after spawning. They spawn therefore but once, 

 and reproduction is followed by death. In specimens which 

 have died in the aquarium in the gravid condition, it was found 

 that all the organs except the ovaries were much reduced, and 

 the skeleton in particular undergoes extraordinary retrogressive 

 changes. The mineral matter disappears from the bones, so 

 that they can be cut like cheese, and the teeth are all lost. 



That the condition is not due to disease, or the result of 

 captivity, is proved by the constancy with which it develops, and 

 by the fact that the ovaries are healthy and rapidly develop. 

 The ova, however, never became perfectly ripe, and have never 

 been shed in the aquarium. In all probability the premature 

 death of the females is due to the absence of natural conditions, 

 especially of the pressure of the water at the depth at which the 

 conger naturally spawns, a depth of at least thirty to forty 



