INSTINCT OF INSECTS. 595 



watched, while soldering the angles of a cell with propolis, detached a 

 thread of this material, with which she entered the cell. Instinct would 

 have taught her to separate it of the exact length required ; but after 

 applying it to the angle of the cell, she found it too long, and cut off a 

 portion so as to fit it to her purpose.^ 



This is a very simple instance ; but one such fact is as decisive in 

 proof of reason as a thousand more complex, and of such there is no 

 lack. Dr. Darwin (whose authority in the present case depending not on 

 hearsay, but his own observation, may be here taken) informs us, that 

 walking one day in his garden, he perceived a wasp upon the gravel 

 walk with a large fly nearly as big as itself which it had caught. Kneel- 

 ing down he distinctly saw it cut off the head and abdomen, and then, 

 taking up with its feet the trunk or middle portion of the body to which 

 the wings remained attached, fly away. But a breeze of wind acting 

 upon the wings of the fly turned round the wasp with its burthen, and 

 impeded its progress. Upon this it alighted again on the gravel walk, 

 deliberately sawed off first one wing and then the other; and having 

 thus removed the cause of its embarrassment, flew off with its booty .^ 

 Could any process of ratiocination be more perfect ? " Something acts 

 upon the wings of this fly and impedes my flight. If I wish to reach 

 my nest quickly, I must get rid of them — to effect which, the shortest 

 way will be to alight again and cut them off." These reflections, or 

 others of similar import, must be supposed to have passed through the 

 mind of the wasp, or its actions are altogether inexplicable. Instinct might 

 have taught it to cut off the wings of all flies, previously to flying away 

 with them. But here it first attempted to fly with the wings on, — was 

 impeded by a certain cause, — discovered what this cause was, and alighted 

 to remove it. The chain of evidence seems perfect in proof that nothing 

 but reason could have been its prompter.'' 



An analogous though less striking fact is mentioned by Reaumur, on the 

 authority of M. Cossigny, who witnessed it in the Isle of France, where 

 the Sphecina are accustomed to bury the bodies of cockroaches along 

 with their eggs for provision for their young. He sometimes saw an insect 

 of this tribe attempt to drag after it into its hole a dead cockroach, which 

 was too big to be made to enter by all its efforts. After several ineffectual 

 trials the animal came out, cut off its elytra and some of its legs, and thus 

 reduced in co'mpass drew in its prey without difficulty.'* 



Under this head I shall mention but one fact more. A friend of Gle- 

 ditsch, the observer of the singular economy of the burying beetle (Necro- 

 phorus vespillo) related in a former letter, being desirous of drying a dead 



» Huber, ii. 268. 2 Zoonomia, i. 183. 



* Mr. Newport has argued, in a paper read to ihe Entomological Society ( TVans. i. 228.), 

 that the instinct of wasps is always to cut off the wings of flies before flying away with 

 them, and that, consequently, the above fact proves nothing as to the reason of insects. 

 Here, however, I must beg to differ from him ; for, supposing Dr. Darwin's statement lo be 

 accuraie, which, from the minute particulars into which he enters, we have no right to 

 doubt, the circumstances of the wasp's first violating its natural instinct by flying away 

 with the fly before cutting off" its wings, and then, on finding the wind act upon them, 

 alighting to do what it had neglected at first, cannot well be explained except on the sup- 

 position of some reasoning process having passed through its mind. In any case, there is 

 no need of this particular fact to prove the existence of reason in insects, of which such 

 numerous other instances have been adduced. 



* Reaum. vi. 283. 



