THE INFANCY OF FISHES 233 



hues, which are especially conspicuous in the male, who 

 is always smaller than the female. The skin becomes 

 silvery, the breast fin black; and, what is really very 

 significant, the eyes become considerably larger. And 

 this because they are to spend the short space of life 

 remaining to them under new and remarkably different 

 conditions. For years they have lived in the mud of 

 some shallow ditch or slow-moving stream, now they are 

 not only to sojourn in the great and wide sea, but they 

 are to descend its awful and mysterious depths, and 

 there, some two hundred fathoms deep, and in a darkness 

 that might be felt (for the light of day never touches these 

 abysses) they fulfil the purpose of their lives and — die. 



How long the eggs of the eel take to hatch is unknown, 

 nor can we say anything of the earliest stages of larval 

 life. But we may safely assume that they do not differ 

 in any essential respect from those which are known to 

 obtain in the life-history of the conger-eel. Sooner or 

 later, however, the young eel becomes transformed into 

 a diaphanous ribbon-shaped creature, with a ridiculously 

 small head and no fins, and with white instead of 

 red blood. Its backbone and the muscles of its body 

 are plainly visible through the skin. What it feeds on 

 during the early days of life we do not know, but it has 

 no large reserve of yolk to draw upon. For a time, 

 anyhow, it feeds, and increases in size in consequence. 



Then a strange thing happens. The mouth has to be 

 closed for alterations : a new set of teeth has to be 

 developed, and other changes made, hence a prolonged 

 fast becomes enforced, and daily the little eel dwindles 

 in size. At the same time it is moving, with millions of 

 its own kind, nearer and nearer to the light, nearer to the 

 sun, and nearer and nearer to the land. What guides 



