INSTINCT OF INSECTS. 549 



the form of their cells when circumstances require it, and that in a way 

 which one would not have expected. 



Having placed in front of a comb which the bees were constructing a 

 slip of glass, they seemed immediately aware that it would be very difficult 

 to attach it to so slippery a surface ; and instead of continuing the comb in 

 a straight line, they bent it at a right angle, so as to extend beyond the slip 

 of glass, and ultimately fixed it to an adjoining part of the wood-work of 

 the hive which the glass did not cover. This deviation, if the comb had 

 been a mere simple and uniform mass of wax, would have evinced no small 

 ingenuity j but you will bear in mind that a comb consists on each side, or 

 face, of cells having between them bottoms in common ; and if you take a 

 comb, and, having softened the wax by heat, endeavour to bend it in any 

 part at a right angle, you will then comprehend the difficulties which our 

 little architects had to encounter. The resources of their instinct, how- 

 ever, were adequate to the emergency. They made the cells on the convex 

 side of the bent part of the comb much larger, and those on the concave 

 side much smaller than usual \ the former having three or four times the 

 diameter of the latter. But this was not all. As the bottoms of the small 

 and large cells were as usual common to both, the cells were not regular 

 prisms, but the small ones considerably wider at the bottom than at the top, 

 and conversely in the large ones! What conception can we form of so 

 wonderful a flexibility of instinct? How, as Huber asks, can we com- 

 prehend the mode in which such a crowd of labourers, occupied at the 

 same time on the edge of the comb, could agree to give to it the same 

 curvature from one extremity to the other; or how they could arrange 

 together to construct on one face cells so small, while on the other they 

 imparted to them such enlarged dimensions ? And how can we feel 

 adequate astonishment that they should have the art of making cells of 

 such different sizes correspond ? l 



After this long but I flatter myself not wholly uninteresting enumeration, 

 you will scarcely hesitate to admit that insects, and of these the bee pre- 

 eminently, are endowed with a much more exquisite and flexible instinct 

 than the larger animals. But you may be here led to ask, Can all this be 

 referred to instinct ? Is not this pliability to circumstances this surprising 

 adaptation of means for accomplishing an end rather the result of 

 reason ? 



You will not doubt my allowing the appositeness of this question, when 

 I frankly tell you that so strikingly do many of the preceding facts seem at 

 first view the effect of reason, that in my original sketch of the letter you 

 are now reading, I had arranged them as instances of this faculty. But 

 mature consideration has convinced me (though I confess the subject has 

 great difficulties) that this view was fallacious; and that though some 

 circumstances connected with these facts may, as I shall hereafter show, be 

 referable to reason, the facts themselves can only be consistently explained 

 by regarding them as I have here done, as examples of variations of particular 

 instincts: and this on two accounts. 



In the first place, these variations, however singular, are limited in their 

 extent: all bees are, and have always been, able to avail themselves of a 

 certain number, but not to increase that number. Bees cemented their 



i Huber, ii. 219. 



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