222 



Genetical Studies in Moths 



that for an explanation of the changes we must look to the passage to 

 birch in the one case and to larch in the other. 



Of this, in the case of size, we can adduce experimental proof very 

 readily; a birch diet quickly restores the pinewood autumnata to its 

 former greater mean size ; nor need the question of changed food delay 



TABLE III. 



T?ie vegetaticni of Wilton Pine Wood, Normanhy Intake Birch Wood and 

 Lonsdale Alder Wood. 



* The frequency symbols are : — A, abundant ; G, common ; 0, occasional ; R, rare ; 

 VR, very rare ; LC, LA, locally common, locally abundant. 



