29 



But how, it may be asked, does this primary adapt- 

 ation to external conditions affect the question of spe- 

 cific development ? Perhaps not much : nevertheless, as 

 lately urged, it is well that such adaptations should be 

 borne in mind, not merely that due importance may be 

 given to influences in conformity with which the creative 

 act was at the first expressly regulated ; but also that we 

 may be prepared, if any qualifying power be admitted to 

 reside in those influences themselves, for the kind of 

 aberration which reason and experience would seem 

 alike to imply that we should, in the various instances, 

 anticipate. 



We have already stated, that climate, when taken 

 alone, does not appear to produce any very decided 

 modifying effect on insect form, seeing that there are 

 vast numbers of species of a wide geographical range 

 which do not display, on their northern and southern 

 limits, differences sufficiently constant to be regarded as 

 purely climatal ones; and it is clear that, if climatal 

 causes of themselves were of real primary significance, 

 we should probably seldom fail to trace out, from their 

 long- continued operation, some steady and positive 

 result. Yet when combined with other principles, there 



tropics. The carrion-feeders and Erachelytra are very uncommon ; 

 on the other hand, the Rhynchophora and Chrysomelidce, all of 

 which depend on the vegetable world for subsistence, are present in 

 astonishing numbers. The orders Orthoptera and Hemiptera are 

 peculiarly numerous; as is, likewise, the stinging division of the 

 Eymenoptera, the bees, perhaps, being excepted." Journal of 

 Researches, p. 34. 



