92 TRANSACTIONS OF THE ILLINOIS 



full million — distinct species of insects in this sublunary worlds of ours, 

 and that their habits and habitations are so diversified, it would really seem 

 as though entomology was a subject too vast for any one man to shoul- 

 der; and indeed it is in all conscience extensive enough. The science of 

 entomology is however so perfect in itself, and its classification is so beau- 

 tiful and simple that a particular species is referred to its Order, its Family, 

 its Genus, and finally separated from the other species of that genus, 

 with the greatest ease, and with a feeling of true satisfaction and triumph, 

 by those who have mastered the rudiments of the science. And, very 

 fortunately, it is not necessary for the practical fruit grower to enter into 

 the ininutiie of species or even of genera in order to learn the habits of 

 the insects which interest him in one way or another. These minutiae 

 must be left to the professed entomologist. 



There is not an insect on the face of the globe which can not be 

 placed in one or the other of seven, or, more properly speaking, eight 

 great Orders; so that, unlike the Botanist, the Entomologist is not 

 bewildered by an innumerable array of these Orders, though he has five 

 times as many species to deal with. These Orders comprise about two 

 hundred families, many of which may, for practical purposes, be 

 grouped into one family — as, for instance, the seven Families of Digger- 

 wasps, and the five large Families which have all the same habits as the 

 ti'ue or genuine Ichneumon-flies. Many more may be neglected as small, 

 rare, or unimportant; so that practically there will remain about a hun- 

 dred family types to be learned. Each family, as Agassiz has well 

 remarked, may, with a little practice, be distinguished at a glance by its 

 general appearance, just as every child, with a little practice, learns to 

 distinguish the Family of A's from the Family of B's, and these from 

 the Family of C's in the alphabet. There is the old English A, the 

 German text A, and a host of ornamental A's, both in the capital letter 

 and the sinall or "lowercase" letter, as the printers call it; but the 

 family likeness runs through them all, and it is astonishing how quick a 

 child learns to distinguish each family type. It is true there are a few 

 abnormal or eccentric insects — there were some which deceived even 

 LiNN^us — which put on the habit of strange families, just as an eel, which 

 is a true fish with fins, puts on the habit of a snake — a rejotile without 

 fins. But these are the exceptions and not the rule. 



Now it is wisely ordained that every family, as a general rule, has 

 not only a distinctive family appearance, but also distinct family manners. 

 For example, nobody ever saw an Ichneumon Fly construct a nest and 

 provision it with insects, as does a Digger-wasp; and nobody ever saw 

 a Digger-wasp deposit its eggs in the body of a living insect at large in 

 the woods as an Ichneumon Fly does. But each family maintains its 

 peculiar family habits, and can not be induced to deviate from them. 



So universally is this the case, that if you bring me an insect which 

 I never saw in my life, I will tell you half its history at a glance. It is this 

 " Unity of Habits;" this beautiful provision of nature — definite family 

 likeness accompanied by definite family habits — which so simplifies the 

 task of the practical man ; for, instead of having to study the diversified 



