Book IV. 



OF VERMIN. 



427 



accompany their parents in quest of food, it is really astonishing the number of eater- 

 pillars they destroy. I can say, from my own observation, that if it was not the case 

 that the birds destroy a vast number of caterpillars, our trees in general would exhibit 

 nothing but bare stumps, for the insects would become as numerous as the locusts of 

 Spain and America. It is from that circumstance that we find so few flies in com- 

 parison of the great number of caterpillars. I one day followed a nest of young ox- 

 eyes, which had just flown, in order to see how the old ones acted. I saw them fly from 

 branch to branch, and pick from the curled leaves the caterpillars, with which they flew 

 to their young to feed them. From these considerations, it is my opinion, that should 

 the o-ardener, instead of pursuing a system of indiscriminate warfare against the 

 feathered tribe, avail himself of the services of these useful allies, he might, with their 

 exertions and his own united, soon rid himself of those insects that have hitherto set his 

 efforts at defiance." (Cal. Mem. hi. 333.) 



2224. The insects which infest plants are almost as numerous as the plants themselves : 

 almost every species having a particular insect which it seems destined by nature to sup- 

 port. Insects are distinguished from quadrupeds, birds, and reptiles, by their more 

 numerous feet, being without bones, and by their head being furnished with a pair of 

 antennae or horns. From the vermes, or worm-like animals, insects are sufficiently dis- 

 tinguished by their having feet. 



2225. Taking a general view of insects we find most of them are oviparous ; of course 

 the first state in which insects appear is that of an ovum or egg. This relates to the 

 generality of insects, for there are some examples of viviparous insects, as in the genera 

 aphis, musca, &c. The eggs of insects (fig. 393.) 393 



are of two sorts : the first membranaceous, like the 

 eggs of the tortoise, and the other reptiles ; the other 

 covered with a shell like those of the birds. Their 

 figure varies exceedingly ; some are round, some 

 elliptical, some lenticular, some cylindrical, some 

 pyramidal, some flat, some square, but the round 

 and oval are the most common. As an example of 

 the various shapes of the eggs of insects, and of 

 their natural as well as magnified size, we refer to 

 those of the common slug (a), phalaena nupta (6), 

 brown-tailed moth (c), currant-moth (rf), common 

 gooseberry-moth (e), turnip-butterfly (f), spider 

 (g), house-cricket (h), and common chafer (i). 



2226. The eggs of insects seldom increase in size, from the time they have been de- 

 posited by the parent, till they are hatched ; those of the tenthredo, however, and of some 

 others, are observed to increase in bulk. At first there is nothing to be perceived in the 

 eggs of insects but a watery fluid ; after some little time, the head, like an obscure point, 

 is observable in the centre. The little insect remains in the egg till its limbs have ac- 

 quired strength to break the egg and make its escape ; the different species of insects 

 remain enclosed in the egg for very different periods ; some continue enclosed only a 

 few days, others remain for several months. The eggs of many insects remain without 

 being hatched during the whole winter, and the young insects do not come forth from 

 them, till the season at which the leaves of the vegetables on which they feed begin to expand. 



2227. The insect in its second or caterpillar state {fig. 394.) has been usually known by 

 the name of eruca or larva, being a sort of masked form or disguise of the insect in its com- 

 plete state. The larvae of insects differ very much from each other, according to the several 

 tribes to which they belong ; those of the butterfly (Pajnlio) and moth (Phalcena) tribes are 

 generally known by the name of caterpillars ; those of the beetle (Scarabceus), except 



