1921.] The Ministry's Scheme of Elvee Distribution. 1169 



ready to breed, travels in the autumn in the reverse direction, 

 from river to ocean. Recent discoveries have shown that with 

 the object of breeding the eel undertakes an immensely long 

 journey, the probable breeding place of all the European eels 

 being far out in the Atlantic. When about to depart, the eel 

 changes its colour from yellow to silver, resembling in this 

 respect, and in its large eyes, the fish that inhabit the ocean 

 at a depth of from 50 to 300 fathoms. The breeding eels never 

 return, but the larvae are carried eastwards and north-eastwards 

 by the North Atlantic drift, and after a long time, probably 

 about two years, become elvers (eel fry). In the spring the 

 elvers make their way to the fresh water, where, after feeding 

 and growing for from 3 to 12 years they become mature 

 silver " eels. 



It has long been known that eels descend to the sea in the 

 autumn and that elvers ascend the rivers in the spring, but 

 it had been assumed until comparatively recently that the 

 elvers were the offspring of the eels which had descended the 

 previous autumn. It was not until 1904 that any definite know- 

 ledge was gained of the breeding habits of the eel, and the 

 exact breeding grounds have only just been discovered by 

 the eminent Danish naturalist, Dr. Johannes Schmidt. 

 Dr. Schmidt has proved that the European eel is not split up 

 into local races, but that only one species exists, and this is found 

 on the coasts and in the rivers of all countries that border the 

 Eastern North Atlantic, from Iceland and Scandinavia to 

 Morocco and Madeira and throughout the Mediterranean. It 

 lives under a variety of conditions, in hot and cold climates, 

 in the sea and in fresh water, in rivers, lakes, brooks and ponds. 



The distribution of the larval eels from the Atlantic breeding 

 ground is determined by the set of the prevalent marine 

 currents. This explains why elvers are most abundant in 

 countries that lie nearest to the Atlantic. Since the stock of 

 each river is thus replenished from a common source, the 

 limitation of the capture of silver eels in any one river is not 

 likely permanently to affect the stock in that river. It follows 

 that the effective method of keeping up or increasing the supply 

 of eels in a healthy river is each season to transport elvers to 

 the river from waters where they are more abundant. 



In view of the discoveries with regard to the breeding habits 

 of eels the German Fisheries Union established in pre-War 

 days a depot at Epney-on- Severn for the supply of elvers to 

 Germany, whence some of the grown eels were subsequently 



