FISHES 



433 



and many different names, which vary with the locahty, are 

 given to the successive stages of life. Our knowledge of the 

 habits of the Salmon still leaves much to be desired, especially 

 as to its life in the sea. 



The life-history of the Common Eel {Anguilla vulgaris) 

 presents us with a curious reversal of events as compared with 

 the Salmon. Until about twenty years ago no male eels had 

 been discovered, but we now know that the so-called " broad- 



Fig. 958. — Salmon {Salvto salar). i, Egg; 2, egg with embryo (enlarged); 3, young larva with yolk-sac 

 (enlarged); 4, Parr; 5, Smolt; 6, Grilse; 7 and 8, adult male and female. 



nosed eels " and " sharp-nosed eels ", long believed to be distinct 

 varieties, are respectively the males and females of this species. 

 Thanks mainly to the painstaking observations of Grassi and 

 Calandruccio, made on the Sicilian coast in 1891-92, the life- 

 history has at last been elucidated as regards its main features. 

 In October and November the adult eels migrate to the deep 

 sea for spawning, after which they most probably die, since 

 there is no reliable evidence of a return to fresh water. The 

 eggs hatch out into larvae of which the early stages are un- 

 known, and we first meet them as transparent flattened creatures 

 devoid of scales, which have long been familiar to naturalists under 



