( ir. ) 



incrediljlc quantities in all waters, and arc Co minute, that millions 

 of them are fcarcely equal to the flze of a grain of fand; and, when 

 we confider that the young fry of pearch, trout, jack, and the like, 

 when only a few days or weeks old, are always obfen^ed fwimming 

 llowly againft the llrcam, we may conclude, that it is with intent 

 the better to catch thofe very minute fiflies, or animalcules, which 

 are carried down the flrcam in the contrary direction, and to feed on 

 them, till they are of lufficient growth to prey on larger filh ; and, 

 if we do but obferve the very large eyes of thofe fmall fry, much 

 bigger in proportion than other parts of their bodies, we may form 

 a tolerable conje6lure, that in the firlt creation, they were appointed 

 to have fuch large eyes, for enabling them the better to difcover and 

 catch thofe minute fiflies which ferve them for prey. 



I have formerly laid it down as a fa6t eltabliflied*, at Icall in my 

 opinion, that fiflies living in rivers or very deep waters, or fuch 

 waters as are always in motion, are not obnoxious to any decay or 

 difeafe, and never die of old age ; and now, to apply that idea to 

 the fubjcdl under confideration. I have examined the fcales of 

 Herrings, and I uniformly drew this conclusion, that all the Herrings 

 caught by our fifliermen were, as far as I could obfcne, barely a 

 year old; in confirmation of which opinion, upon infpcAing Her- 

 rings caught about the beginning of the month of June (which were 

 procured privately, or as it were by fl:calth, becaufc, by our laws, 

 Herrings are not then permitted to be taken), they being fometimes 

 lent to me as prefcnts, I always found them to be of a much fmaller 

 flze than thofe caught a month or two later; and [ have thought that 

 perhaps all Herrings caught in Ihe North Sea ifliied from the roes 

 or fpawn which had been depofited the preceding year. Now, if we 

 lay it down as a certain fact, that all the kinds of fifli to us known ! 

 when they firfl; begin to lay their eggs or fpawn, are not a year old, 

 and that the greater part of thofe Herrings, which are found on 

 thefe coalls in any one year, dcpofite the eggs from whence ifluc all 



* Sec vol. I. p. 71. 



X 



