EELS AND THEIR YOUNG. 257 



rivers in the summer ; and some idea of the numbers of these young 

 eels, each about three inches long, may be gathered from the rec- 

 ord of Dr. William Roots, who lived at Kingston in 1832. He cal- 

 culated that from sixteen to eighteen hundred passed a given point 

 in the space of one minute of time. These baby-eels travel only by 

 day and rest by night. In large and deep rivers, where they probably 

 find the current strong, they form themselves into a closely compacted 

 company, " a narrow but long-extended column," as it has been de- 

 scribed ; but in less formidable streams they abandon this arrangement 

 and travel, each one more or less at his own sweet will, near the bank. 

 The perseverance of these little creatures in overcoming the obstruc- 

 tions they may encounter is quite extraordinary. The large flood- 

 gates, sometimes twenty feet high, that are to be met with on the 

 Thames would be sufficient, one would imagine, to bar the progress 

 of a fish the size of a darning-needle. But young eels have a whole- 

 some idea that nothing can stop them, consequently nothing does. As 

 one writer says, speaking of the way in which they ascend flood-gates 

 and such like barriers, " Those which die stick to the posts ; others 

 which get a little higher meet with the same fate, until at last a suffi- 

 cient layer of them is formed to enable the rest to overcome the diffi- 

 culty of the passage." The mortality resulting from such "forlorn 

 hopes" greatly helps to account for the difference of number between 

 the upward migration of young eels and the return of comparatively 

 few down-stream in the autumn. In some places these baby-eels are 

 much sought after, and are formed into cakes which are eaten fried. 

 On one occasion at Exeter two cart-loads of these little fish, not larger 

 than darning-needles, were sold, each cart-load weighing four hundred- 

 weight. They were sold for fourpence per pound. The term elver, 

 which, as we have said, is in some places indiscriminately used to de- 

 note all young eels, in reality only belongs to the " transparent " eels 

 which are occasionally found among their more opaque brethren. 

 These elvers are so transparent that most of the internal organs and 

 the action of the heart and blood-vessels can easily be seen. Little is 

 known of them. They are not supposed to form a distinct species, for 

 they have been found with the characteristics of both sharp-nosed and 

 broad-nosed eels. They have been met with in the rivers in January 

 as well as in June, and, even when caught and confined in a tank, they 

 in no way grow out of their peculiar transparency ; so they have re- 

 mained one of the many mysteries of the eel family till now. They 

 are doubly interesting to study on account of this transparency. One 

 of the greatest peculiarities possessed by eels is that they have a sec- 

 ond heart situated in the extremity of their tails ; of course, in the 

 transparent elvers the action of this heart can be more easily noted 

 than in the ordinary eels. In all, however, its action is plainly mani- 

 fest, especially if the fish has been out of water any time or exhausted, 

 a fact known to the street venders of live eels, who therefore are care- 



VOL. XXIX. 17 



