CYPRESS-SPURGE CATERPILLAR. 181 



provision for a future progeny, the instinct is in- 

 variably subtle and extraordinary. What, for in- 

 stance, is more remarkable than that the insect should 

 always place her eggs where her progeny will find 

 the food which is best suited to their nature ? In 

 almost no case does the perfect insect eat that 

 food, so that the parent cannot judge from her own 

 habits. The Contriver of the mechanism by which 

 insects work also directs the instinct by which they 

 use their tools. 



It is exceedingly difficult, with our very hmited 

 knowledge of the springs of action in the inferior 

 animals, to determine the motives of their industry — 

 that is, whether they see clearly the end and object 

 of their arrangements. A human architect, in all his 

 plans, has regard, according to the extent of his skill, 

 to the combination of beauty and convenience; and 

 in most cases he has adaptations peculiar to the cir- 

 cumstances connected with the purpose of the struc- 

 ture. In the erection of a common dwelling-house, 

 for instance, one family requires many sleeping- 

 rooms, another few — one wants its drawing-rooms 

 in a suite, another detached. The architect knows all 

 these wants, and provides for them. But all insects 

 build their habitations upon the same general model, 

 although they can slightly vary them according to 

 circumstances. Thus, according as the uniformity, 

 or the occasional adaptation of their work to particu- 

 lar situations, has been most regarded by those who 

 speculate upon their actions, they have been held to 

 be wholly governed by instinct or by intelligence — 

 have been called machines or free agents. There are 

 difficulties in either conclusion; and the truth perhaps 

 lies between the two opinions. Their actions may 

 entirely result from their organization; they are cer- 

 tainl}' in conformity with it. Those who would deny 

 the animal all intelHgence, by which we mean a power, 



VOL. IV. 16 



