LETTER XXVII. 



ON THE INSTINCT OF INSECTS. 



She greater part of those surprising facts connected 

 with the manners and economy of insects, of which the 

 relation has occupied the preceding letters, is to be re- 

 ferred, I have told you, to their instinct. But what^ 

 you will ask, is this instinct ? — of what nature is this 

 faculty which produces effects so extraordinary ? 



To this query I do not pretend to give any satis- 

 factory answer. As I am quite of Bonnet's opinion, 

 that philosophers will in vain torment themselves to 

 define instinct, until they have spent some time in the 

 head of an animal without actually l)d7ig that animal 

 — a species of metempsychosis through which I have 

 never passed — I shall not attempt to explain what 

 this mysterious energy is. It will not, however, I 

 imagine, be very difficult to show what it is not ; and 

 some observations vfith this view, followed by an enu- 

 meration of peculiarities v* hich distinguish the instincts 

 of insects from those of other tribes of animals, anda 

 short inquiry whether tlieir actions are guided solely 

 by instinct, ^'i ill form the substance of this letter. 



I. It is quite superfluous at this day to controvert 

 the explanations of instinct advanced by some of the 

 philosophers of the old school, such as that of Cud- 



VOL. II. 2h 



