88 INSECT TRANSFORMATIONS. 



remarkable manner. The mother deposits her eg:ij;8 

 under her body, which becomes glued to the spot ; 

 she then dies, and her body becomes a covering for 

 the eggs. In this state the insects appear on the bark 

 of trees like small warts, some species in the form of 

 a boat, some kidney-shaped, and others globular ; 

 and, before their history was understood, they were 

 with some plausibility supposed to be vegetable galls, 

 — whencethey were termed Gall Insects hy the French. 

 Though the mother insect is seldom larger than a 

 peppercorn, the number of eggs which she lays 

 amounts to several thousands, and in fact fills the 

 greater portion of her body. Those which are found 

 on our green-house plants, and which are the pest of 

 the grape-vines in the neighbourhood of London, 

 both in and out of doors, secrete a sort of white 

 silky gum, very like gossamer, as the first bed of 

 their eggs. Reaumur could not discover that the 

 mother insect was furnished with any organ similar 

 to those of spiders and caterpillars for spinning this 

 gossamer ; and in an allied genus {Dorthesia)^ Kirby 

 and Spence talk of it as " wire-drawn through nu- 

 merous pores in certain oval plates in the skin*." 

 Having minutely observed, during several successive 

 summers, some thousands of the female cocci found 

 on vines in the open air, we have satisfied ourselves 

 that this cottony matter is precisely similar to the 

 gluten which envelopes the eggs of most insects ; 

 and that it is neither spun like the threads of cater- 

 pillars, or the webs of spiders, nor wire drawn 

 through numerous pores, — but is simply excluded 

 along with the eggs. We may remark, also, that the 

 covering formed by the body of the mother coccus 

 prevents this substance from drying, as the webs of 

 spiders do ; and, consequently, it can at any time be 



* Introd. iii., p. 183. 



