NATURAL HISTORY. 



840 



Instinctive cunning ; for, being an 

 easy prey, when discovered, to 

 otters, herons, and other nocturnal 

 enemies, it is only in the darkest 

 nights that they can travel in safe- 

 i ty. During the period of their 

 I run, vast quantities are caught in 

 I bag-nets set across the streams. 

 [ There is reason to suspect that all 

 the eels in rivers do not run for 

 the sea, as vei'y early in the spring 

 large eels abound in rivers at such 

 a distance inland, as renders it 

 highly improbable that they can 

 have ascended so far at so early a 

 period ; and, indeed, it is yet an 

 unascertained fact, whether, of the 

 vast multitude which unquestion- 

 ably do pass downwards to the sea, 

 any of them do again return and 

 ascend to any distance up the 

 streams. If, indeed, this retro- 

 grade emigration really existed to 

 any extent, there are thousands of 

 situations on our streams where it 

 must have been every season per- 

 ceived ; and yet it has not only 

 not been discovered, but the in- 

 stances are frequent, where the ob- 

 stacles on many of our streams 

 render it impracticable, and where, 

 nevertheless, large eels are found 

 above these obstacles as early and 

 as abundant as below them. The 

 probability, therefore is, that few 

 or none of the vast numbers which 

 descend the streams ever again re- 

 turn ; and then, as they are never 

 discovered in the sea itself, the 

 question of what ultimately be- 

 comes of them, is just as obscure 

 as that of their generation. 



There are many lakes, and mul- 

 titudes of pools, abounding with 

 eels, and from which they cannot 

 run on account of the insufficiency 

 of the outlets ; and in these situa- 

 tions the eels most certainly conti- 

 VoL. LI. 



nue during the period of their ex- 

 istence. There, however, they re- 

 gularly disappear in winter, and 

 the maimer of their hibernating is 

 entirely unknown; but as no spe- 

 cies of animal with whicii we are 

 acquainted ever does breed during 

 the time of its hibernation (the 

 thing, indeed, seeming physically 

 impossible), and as eels in these 

 confined situations are taken at all 

 other times, without any vestige 

 of propagation being discovered 

 amongst them, the inference seems 

 conclusive, that eels never do, un- 

 der any circumstance, breed in 

 fresh water. Were it indeed, prac- 

 ticable in a single instance, it would 

 be equally so in thousands of others 

 where the circumstances are so 

 similar ; and it would be passing 

 strange if a solitary quarry-pit, 

 which had been excluded for a do- 

 zen years even from day-light, 

 were to discover to us an occurrence 

 which is never displayed in our 

 multitudinous open pools, where 

 the same animals are equally re- 

 stricted from escape. 



In contradistinction to the vast 

 emigration of old eels down the 

 streams in autumn, an immensely 

 greater migration of young ones 

 commences up the streams in 

 spring and summer. Their size 

 varies between the smallest and the 

 largest darning needle. They are 

 called elvers, and abound in some 

 of our large rivers to an inconceiv- 

 able extent. In some places bush- 

 els of them are taken with baskets 

 fixed on to the ends of poles, and 

 drawn swiftly tlirough the water. 

 Their progress is always along the 

 banks, and numerous portions piiss 

 up into all the lateral streams. The 

 smallest brook and the minutest rill 

 that can runreceivetheirproportion; 



3 I and 



