INTRODUCTORY DISCOURSE. 31 



laws which govern this fish are peculiar : the eel goes to the sea for pro- 

 duction, and the young ones attain their growth and maturity in tresh 

 water. 



The mildains and other artificial obstacles in rivers against the ascent 

 of anadromous fishes have, in some places, entirely expelled them ; and 

 in others diminished their number. The salmon, if we may credit the 

 account of Hudson's voyage, formerly visited this river : he is now an 

 entire stranger, and he is retiring very rapidly from the Connecticut river 

 and from several streams that flow into the western lakes.(28) The dis- 

 appearance of fish for years, as for instance the lobster during the revo- 

 lutionary war, and sometimes the visits of strange fish, are circumst mces 

 deserving of observation. The best mode of multiplying and preserving 

 shellfish would be a subject useful to investigate ; and why might we not 

 increase our fre^h-water fish by importing the carp aiid tench for propa- 

 gation, as was formerly done in Great Britain 1(29} 



The Linnoean classes of amphibia, vermes, and insects, hare been 

 almost entirely overlooked ; and yet what an immense field for inquiry 

 do they present ? There are, it is estimated, twenty thousand species 

 of insects; twenty species feed on the apple tree alone, seventeen of 

 which are phala?nas (millers.) There are seventy-five species of the 

 aphis (plant louse,) so destructive to vegetation. The ravages of the 

 weavil, hessiau fly, canker worm, palmer worm, grass worm, and rose 

 bug, are incalculably injurious. Dr. Barton has intimated t! .it several 

 of our animals supposed to be indigenous may be of european origin. 0) 

 Be this as it may ; we know that noxious insects of native origin, migrate 

 from native to naturalized vegetables as they furnish more abundant or 

 agreeable food. Different preventives and remedies have been pre- 

 scribed for their depredations, but it still remains to discover rfft'?:ual 

 ones. Silk worms are cultivated with great success in some parts of the 

 country, and excellent silk is made. It has been disputed whether the 

 apis mellifica, or honey bee, has not been imported into America 1 Jef- 

 ferson and Barton say it has; Belkuap has taken opposite ground. Oie 

 would suppose that Cortez had settled this question in his letters to the 

 emperor Charles V., which describe all the commodities vended in the 

 great market of Mexico, where, he says, " There is soid honey of bees 

 and wax : honey from the stalks of maize which are as sweet as sugar, 

 and honey from a shrub called by the people maguey." Lewis and 

 Clarke, in their journey to the Pacific Ocean, did not observe the honey 

 bee after they left the Osage indians.(31) 



Our ophiology is, of course, of a very limited range. We have be- 

 twpon thirty and forty species of serpents ; the most remarkabl" one, 

 the rattlesnake, crotalus horridus, not being able to exist in the vicinity 

 of swine, has fled from the Cultivated ; ou;.'ry. h ;* tr ; f i<i appre- 

 hension of danger, the young retreat rate the mouth of the mother for 

 mfetv ?(32) 



