YALE AGRICULTURAL LECTURES. 25 



is legion. And what lias rendered the situation of our farmers 

 and fruit-growers most vexatious, they have been obliged to 

 remain in ignorance, no definite information respecting the 

 names and habits of these creatures, from which they are sus 

 taining such losses, being accessible to them. Only two works 

 on this subject have ever appeared, and neither of these has 

 been on sale in the bookstores. One of them is Dr. Harris's 

 Treatise, originally prepared as part of the Natural History 

 Survey of Massachusetts. The other is Dr. Fitch's own Report 

 on Noxious Insects, published each year in the New York 

 Agricultural Society's Transactions, and also issued separately, 

 two volumes being now completed. 



The insect is divided into three principal parts, viz. : head, 

 thorax or fore-body, and abdomen or hind-body. The head in 

 insects is furnished with antennas or horns, which possess re 

 markable sensitiveness. Thus, an ichneumon fly, by touching 

 them against the outer surface of the bark of a tree in which a 

 worm is lying, detects not merely its presence, but its exact 

 position, although imbedded two or three inches in the solid 

 wood, so accurately that with its long ovipositor or sting it is 

 able to pierce the wood to where the worm lies, and puncture 

 its skin and insert an egg therein. And two bees or ants 

 meeting, by merely touching their horns together, know if they 

 belong to the same hive or hillock for all the world as though 

 there was a system of Freemasonry among them, whereby they 

 know on this shaking hands as it were, whether they are 

 brothers or strangers to each other. 



The most wonderful thing about insects is their metamor 

 phoses, or transformations, the same individual appearing at dif 

 ferent times under forms as different as for a serpent to change 

 into an eagle. There are four of these forms or stages in the 

 growth of insects : first, the egg ; second, the larva or growing 

 stage, when it is a worm or caterpillar ; third, the pupa or 

 dormant stage, when it is often enclosed in a cocoon ; fourth, 

 the perfect insect, when it is a fly, butterfly, beetle, bee, &c. 

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