TILL SCHMIDT'S IN 1904 253 



sexually undeveloped — of only moderate size to traverse 3000 

 or 4000 miles of an ocean full of foes, and to seek, especially 

 to find, the only area which contains the requisite depth, 

 temperature, and currents favouring the procreation and the 

 return home of their minute but parentless progeny. 



The conclusion is now clear that the Eels of Europe at any 

 rate have a spawning area in common ; the two Italian doctors 

 were wrong in supposing that Eels spawned in the Mediterranean. 

 In such ocean depths certainly below, probably far below, the 

 one hundred fathoms ^ Une the generative organs of the Eels 

 develope, and in due though protracted time the females 

 spawn. 2 



Their eggs float for a time ; the young, when hatched out, 

 pass through a metamorphosis and are known in one stage 

 as Leptocephalus brevirostris. This larval form, which is flat 

 and transparent and has a very small head, drifts with the ocean 

 currents towards the coasts of Europe, where it passes through a 

 series of metamorphoses into the Elver or young Eel, which in 

 March and April swims up EngUsh rivers. The fecundity of 

 the Eel, were it not for the system of check and countercheck 

 devised by Nature, would in time become a danger ; for the 

 ovary of a female thirty-two inches in length has been estimated 

 to contain no fewer than 10,700,000 eggs ! ^ 



But however legitimate or illegitimate their methods may 

 seem, all praise should be rendered to our ancient anglers. 

 Especially so, when we call to mind that, as they possessed 

 not running Unes, reels, gut, nor probably landing nets, the 

 playing of large fish must have required more delicate manipula- 

 tion and the landing presented far greater difficulties than to us, 

 armed as we are with all these and many other appliances. 



^ J. Schmidt found the youngest known stages of Leptocephalus, the larval 

 stage of eels, to the west of the Azores, where the water is over 2000 fathoms 

 deep : they were one-third of an inch in length and so were probably not long 

 hatched. 



2 It is believed that no Eels return to the rivers, and that they die not long 

 after procreation. " They commence the long journey, which ends in maturity, 

 reproduction, and death." Presidential Address, British Association, 

 Cardiff, 1920, 



* There is in the Natural History Museum at South Kensington an excellent 

 collection of specimens, illustrative of the development of the Eel. 



