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INSTINCT OF INSECTS. 559 
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 sub- 
stance; 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 opera- 
tion, or to define precisely the limits of each, instances of these mived 
actions are sufficiently common:among animals to leave little doubt of the 
fact. It is instinct which leads a greyhound to pursue a hare ; 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 
instinet 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 neighbours protected themselves against the attacks of the death’s head 
moth (Acherontia atropos), laid before you in a former letter, by so closing 
the entrance of the hive with walls, arcades, casements, and bastions, 
built of a mixture of wax and propolis, that these insidious marauders 
could no longer intrude themselves. 
We can scarcely attribute these elaborate fortifications to reason 
simply ; for it appears that bees have recourse to a similar defensive ex- 
pedient when attacked even by other bees, and the means employed seem 
too subtle and too well adapted to the end to be the result of this faculty 
ina bee. 5 
But, on the other hand, if it be most probable that in this instance in- 
stinct was chiefly concerned, if we impartially consider the facts, it seems 
impossible to deny that reason had some share in the operations. Pure 
instinct would have taught the bees to fortify themselves on the jirst 
attack. If the occupants of a hive had been taken unawares by these 
gigantic aggressors one night, on the second, at least, the entrance should 
have been barricadoed. But it appears clear, from the statement of 
Huber, that it was not until the hives had been repeatedly attacked and 
robbed of nearly their whole stock of honey, that the bees betook them- 
selves to the plan so successfully adopted for the security of their remain- 
ing treasures ; so that reason, tanght by experience, seems to have called 
into action their dormant instincts.$ 
If it be thus probable that reason has some influence upon the actions 
of insects which must be mainly regarded as instinctive, the existence of 
this faculty is still more evident in numerous traits of their history where 
instinct is little if at all concerned. An insect is taught by its instincts 
the most unerring means to the attainment of certain ends ; but these 
ends, as I have already had occasion more than once to remark, are 
limited in number, and such only as are called for by its wants in a state 
of nature. We cannot reasonably suppose insects to be gifted with 
instincts adapted for occasions that are never likely to happen. If, 
1 Huber, ii. 219. 2 Hume's Lssay on the Reason of Animals. 
5 Huber, ii. 289, 
