THE LOUSE KIND. 



teased by them ; the whale, the shark, the 

 sahnon, and the lobster, are not without their 

 company; while every hot-house, and every 

 garden is infested with some peculiarly de- 

 structive. Linnaeus tells us, that he once 

 found a vegetable-louse upon some plants 

 newly arrived from America; and, willing to 

 trace the little animal through its various 

 stages, he brought it with him from London 

 to Leyden, where he carefully preserved it 

 during the winter, until it bred in the spring; 

 but the louse it seems did not treat him with 

 all the gratitude he expected ; for it became 

 the parent of so numerous a progeny, that it 

 soon overrun all the physic-garden of that 

 beautiful city ; and leaves, to this day, many 

 a gardener to curse the Swede's too indul- 

 gent curiosity. 



The animal w'liich some have called the 

 Leaf-louse, is of the size of a flea, and of a 

 bright green.or bluish-green colour; the body 

 is nearly oval, and is largest and most convex 

 on the hinder part ; the breast is very small, 

 and the head is blunt and green : the eyes 

 may be seen very plainly, being prominent 

 on the fore part of the head, and of a shining 

 black colour; near these there is a black 

 line on each side ; and the legs are very slen- 

 der. 



Those animals are usually found upon the 

 leaves of the orache, and other plants; and 

 (he weaker the leaves and buds are, these 

 insects swartn upon them in greater abun- 

 dance. Some plants are covered over with 

 them; though they are not the cause of the 

 plant's weakness, but the sign: however, by 

 wounding and sucking the leaf, they increase 

 the disease. They generally assume their 

 colour from the plant on which they reside. 

 Those that feed upon pot-herbs and plum- 

 frees, are of an ash-colour; only they are 

 greenish when they are young: those that 

 belong to the alder and cherry-tree, are 

 black; as also those upon beans, and some 

 other plants : those on the leaves of apples 

 and rose-trees, are white; but as they leap, 

 like grasshoppers, some place them in the 

 number of the flea kind. The most uncom- 

 mon colour is reddish; and lice of this sort 

 may be found on the leaves of tansey ; and 

 their juice, when rubbed in the hands, tinges 

 them with no disagreeable red. All these 



NO. G3 & 64. 



live upon their respective plant; and arc 

 often engendered within the very substance 

 of the leaf. 



All these bring forth their young alive; 

 and the fetus, when it is ready to be 

 brought forth, entirely fills the belly of the 

 female ; its fore parts being excluded first, 

 and then the hinder. The young one does 

 not begin to move till the horns or feelers 

 appear out of the body of the old one ; and 

 by the motion of these it first shows signs of 

 life, moving them in every direction, and 

 bending all their joints. When the horns and 

 head are excluded, the two fore feet follow, 

 which they move with equal agility; after 

 this follow the middle feet, and then the 

 hinder: still, however, the young one con- 

 tinues sticking to its parent, supported only 

 at one extremity, and hanging, as it were in 

 air, until its small and soft members become 

 hardened and fitted for self-support. The 

 parent then gets rid of its burden; by moving 

 from the place uhere she was sitting, and 

 forcing the young one to stand upon its legs, 

 leaves it to shift tor itself. 



As the animal has riot far to go, its provi- 

 sions lying beneath it, during the summer it 

 continues to eat and creep about with great 

 agility. But as it is viviparous, and must 

 necessarily lurk somewhere in winter, where 

 its body may be defended from the cold, it 

 endeavours to secure a retreat, near the trees 

 or plants that serve to nourish it in the be- 

 ginning of spring. They never hide them- 

 selves in the earth, like many other insects, 

 because they have no part of their bodies 

 fitted lo remove the earth; nor can they 

 creep into every chink, as their legs are too 

 long: besides, their bodies are so tender, 

 that the least rough particle of the earth 

 would hurt them. They, therefore, get into 

 the deep chinks of the bark, and into the 

 cavities of the stronger stalks, from whence 

 they sally out upon the branches and leaves, 

 when the warmth of the sun begins to be felt. 

 Neither the cold in the autumnal season, nor 

 the lesser degree of heat in the spring, ever 

 hurts them ; they seldom, therefore, seek for 

 hiding-places before the fall of the leaf, and 

 are alert enough to take the earliest advan- 

 tage of the returning spring. 



Like many other insects, they cast their 

 5N 





