198 SALMONIA. [SEVENTH DAT. 



and five or six feet perpendicular. He says, when 

 they first rose out of the water upon the dry board, 

 they rested a little which seemed to be till their 

 slime was thrown out, and sufficiently glutinous, 

 and then they rose up the perpendicular ascent with 

 the same facility as if they had been moving on a 

 plane surface. (Trans. Abr. vol. ix. p. 311.) There 

 can, I think, be no doubt, that they are assisted by 

 their small scales, which, placed like those of serpents, 

 must facilitate their progressive motion:* these scales 

 have been microscopically observed by Leuenhoeck. 

 (Phil. Trans, vol. iv.) Eels migrate from the salt 

 water of different sizes, but I believe never when 

 they are above a foot long and the great mass of 

 them are only from two and a half to four inches. 

 They feed, grow, and fatten in fresh water. In small 

 rivers they are seldom very large ; but in large deep 

 lakes they become as thick as a man's arm, or even 

 leg ; and all those of a considerable size attempt 

 to return to the sea in October or November, 

 probably when they experience the cold of the first 

 autumnal rains. Those that are not of the largest 

 size, as I said before, pass the winter in the deepest 

 parts of the mud of rivers and lakes, and do not seem 

 to eat much, and remain, I believe, almost torpid. 



* [Relative to this opinion, and the following one, that the conger 

 and eel are not distinct species, see additional note at the end of the 

 volume. J. D.] 



