THE FAMILY OF EET.S. 313 



mentioned, until the autumnal equinox; beyond which no more 

 have been discovered. The hindrances here referred to are the 

 accident of a muddy condition of the water, which is distasteful 

 to the old Eels as well as to the young, so that the former 

 will quit a river or pool to avoid it; and also a very low state 

 of the stream, when they do not avoid it or lie still from the 

 merely deficient quantity of water, for a dribbling of what is 

 pure will lead them onward, but from its polluted condition, 

 of which these fish are quickly sensible. When thus situated 

 in consequence of the dryness of the season, no Eels have 

 been seen to pass for five or six weeks; while afterwards an 

 abundant fall of rain has been soon followed by an upward 

 migration; which at this early stage of their existence appears 

 to be essential to their well-being. 



But although delayed by a muddled or nauseous condition 

 of the water, Eels are not to be hindered by mechanical 

 difficulties; and it is amusing to trace the means to which they 

 have recourse in passing over barriers that might seem inac- 

 cessible to their efforts. It was at a time when a moderate 

 but rapid stream had from dry weather become a small cascade, 

 that the only way of ascent was up the declivity of a perpen- 

 dicular rock, from which on one side hung some moss and 

 herbage into the water below. When these Eels in succession 

 came to this place they moved about rapidly near where the 

 stream fell down from above, and presently disappeared; when 

 looking more closely it was seen that on one side of the pro- 

 jecting rock they had crept among the fibres of the moss that 

 hung downward, and were moving upwards with wriggling 

 motion, like worms; but resting at times and taking care to 

 keep at a safe distance from the falling current. At last they 

 reached the top and settled into rest, with the head a little 

 stretched out into the river; but after a time, seizing a favourable 

 moment of recovered energy, they put out their renewed strength 

 and moved upward in the stream. Those of them, however, 

 which had taken the other side of the rock were differently 

 situated, and their task was to thrust themselves over a sloping 

 surface by dint of their unaided exertions; in accomplishing 

 which some quitted the water altogether; but they still kept 

 on a moist portion of the ascent, up which by a slow and 

 laboriously serpentine action they contrived to urge their way 

 VOL. IV. 2 s 



