INCREASE IN SIZE OF EGGS. 



121 



of the eggs of some increasing in size during the pro- 

 cess of hatching. The fact a|)pears to have first heen 

 noticed by the celebrated Vallisnieri in his observa- 

 tions on saw-flies {TerdhredinidcB, Leach).* Other 

 instances were subsequently discovered by R aumur, 

 De Geer, Derhani, R' sel, and the younger Huber. 

 * It ought not,' says R aumur, speaking of gall flies 

 { Cijnipidce, 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 spe- 

 cies when they proceed from the body of the fly, or 

 even when they are taken from the mother fly near the 

 thne of their being laid. The whole of those I took 

 from the mother iBies which I killed were remarkably 



Generation of a water-mite (Hi/dra'-hvn abstenrens). 

 a a, the water scoipion, in wlicise l)ody the mite fixes her eggs. 

 fe 6, a magnifietl view of one of its claws, c, a tooth-iike proce>s for 

 restraining the motion of the joint, rf, the watei mite. <, 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. 

 VOL. VI. II 



