43 



desirable that I should offer a few words on the effect of 

 sudden exceptions to the ordinary routine of things, 

 such as, for instance, seasons of peculiar intensity. It 

 does not however appear that any very important modi- 

 fications do often occur from conditions thus abnormal, 

 and as it were accidentally brought about : on the con- 

 trary, indeed, it is a well-known fact, that the members 

 of the insect world are singularly independent of such 

 contingencies ; and that, in the same manner as their 

 times of maturation are neither hastened nor retarded 

 by them, their external development is for the most 

 part free from their control. Yet, in spite of this, 

 specific results are wont to happen, ever and anon, from 

 such circumstances, as though it were a fundamental 

 axiom, that every agent which Nature can press (regu- 

 larly or irregularly) into her service should have, though 

 it may not always exercise its privilege, some qualifying 

 voice. 



I believe that almost the only deviation from the 

 typical state, in insect form, which has been observed to 

 originate, par excellence, from the occasional continu- 

 ance of undue heat or cold, is curiously enough an or- 

 ganic one, having reference to the enlargement of the 

 wings. Every entomologist must be aware that a vast 

 proportion of the Coleoptera (especially the Carabida) 

 are subject to great inconstancy in their metathoracic 

 organs of flight. Many species, as the common Calathus 

 mollis of our own country (to which my attention has 

 been more particularly drawn by the Rev. J. F. Daw son), 



