[NCREASE IN SIZE OP EGGS, 



121 



of the eg'gs of some increasing in size during the pro- 

 cess of hatching. The fact appears to have first been 

 noticed by the celebrated Vallisnieri in his observa- 

 tions on saw-flies (TenthredinidcB, Leach)*. Other 

 instances were subsequently discovered by Reau- 

 mur, De Geer, Derham, Rosel, and the younger 

 Huber. "It ought not," says Rdaumur, speaking of 

 gall-flies (Cy?iipid{B, Westwood), "to be passed in 

 silence, that the egg which I found in the gall appeared 

 to me considerably larger than the eggs of the same 

 species when they proceed from the body of the fly, 

 or even when they are taken from the mother fly 

 near the time of their being laid. The whole of 

 those I took from the mother flies which I killed were 



Generation of a water-mite {^HydracTina abstcrgens). 

 a a, the water-scorpion, in whose body the mite fixes her eggs. 

 hb,a magnified view of one of its claws, c, a tooth-lilse process 

 for restraining: the motion of the joint, d, the water-mite, c, a 

 greatly magnified view of one of its eggs. /, the hook by which 

 It is inserted into the body of the scorpion. 



*See Insect Architecture, pp. 157-8. 



