592 INSTINCT OF INSECTS. 



What I advance, therefore, on this head, I wish to Jje regarded rather as 

 conjectures, that, after the best consideration I am able to give to a subject 

 so much beyond my depth, seem to me plausible, than as certainties to 

 which I require your implicit assent. 



That reason has nothing to do with the major part of the actions of insects 

 is clear, as I have before observed, from the determinateness and perfection 

 of these actions, and from their being performed independently of instruc- 

 tion and experience. A young bee (I must once more repeat) betakes 

 itself to the complex operation of building cells with as much skill as the 

 oldest of its compatriots. We cannot suppose that it has any IcnowJedge 

 of the purposes for which the cells are destined ; or of the effects that 

 will result from its feeding the young larvae, and the like. And if an 

 individual bee be thus destitute of the very materials of reasoning as to 

 its main operations, so must the society in general. 



Nor in those remarkable deviations and accommodations to circum- 

 stances, instanced under a former head, can we, for considerations there 

 assigned, suppose insects to be influenced by reason. These deviations 

 are still limited in number, and involve acts far too complex and recondite 

 to spring from any process of ratiocination in an animal whose term of 

 life does not exceed two years. 



It does not follow, however, that reason may not have a part in inducing 

 some of these last-mentioned actions, though the actions themselves are 

 purely instinctive. I do not pretend to explain in what way or degree 

 they are combined ; but certainly some of the facts do not seem to admit 

 of explanation, except on this supposition. Thus, in the instance above 

 cited from Huber, in which the bees bent a comb at right angles in order 

 to avoid a slip of glass, the remarkable variations in the form of the cells 

 can only, as I have there said, be referred to instinct. Yet the original 

 determination to avoid the glass seems, as Huber himself observes, to 

 indicate something more than instinct, since glass is not a substance 

 against which nature can be supposed to have forewarned bees, there 

 being nothing in hollow trees (their natural abodes) resembling it either 

 in polish or substance ; and what was most striking in their operations 

 was, that they did not wait until they had reached the surface of the glass 

 before changing the direction of the comb, but adopted this variation at a 

 considerable distance, as though they foresaw the inconveniences which 

 might result from another mode of construction.^ However difficult it 

 may be to form a clear conception of this union of instinct and reason in 

 the same operation, or to define precisely the limits of each, instances of 

 these mixed actions are sufficiently common among animals to leave little 

 doubt of the fact. It is instinct which leads a greyhound to pursue a 

 liare ; but it must be reason that directs " an old greyhound to trust the 

 more fatiguing part of the chase to the younger, and to place himself so 

 as to meet the hare in her doubles."^ 



As another instance of these mixed actions in which both reason and 

 instinct seem concerned, but the former more decidedly, may be cited the 

 account which Huber gives of the manner in which the bees of some of 

 his neighbors protected themselves against the attacks of the death's head 

 moth (^Achcrontia apropos), laid before you in a former letter, by so closing 



' Huber, ii. 219. * Hume's Essay on the Season of Animals. 



