THE COMMON HERRING. 179 



they are found in the British Channel in September, 

 but leave it when the sun is at too great a distance 

 from them, and push for a more agreeable climate. 

 And when the weather in America becomes too 

 Warm in May, (after having deposited their eggs,) 

 they steer the course which leads to the cooler 

 northern seas, and, by this careful change of place, 

 perpetually enjoy the temperature of the climate 

 best suited to their nature. 



The voung do not follow the old ones in their first 

 migrations; for they are to be seen in great shoals in 

 all the American bays till the autumn, when they 

 disappear. Since it appears that the Herrings 

 have a natural propensity to keep at a certain distance 

 from the sun, we may conclude that, at this season 

 of the year, the young are led in a direction contrary 

 to that of the old ones, which they meet about lati- 

 tude 23 ° north, and 70 west longitude. Here they 

 are supposed to tack about, and follow the others. 

 These, being larger and stronger, come first into the 

 American harbours ; their numbers, however, are 

 then considerably diminished by the devastations 

 committed among them during their absence*. 



The fecundity of the Herring is astonishing : it 

 has been calculated that, if the offspring of a sin- 

 gle Herring could be suffered to multiply unmo- 

 lested and undiminished for twenty years, they 

 would exhibit a bulk of ten times the size 

 of the earth. But happily Providence has so ex- 



* Gilpin on Herrings, in Amer. Phil. Tran. ii. 236, 



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