186 French National Institute. 



naturalists admit it. Afterwards he endeavours to explain 

 physically how these animals, and children also, learn to 

 suckle : he shows that several f pecies have the power of 

 emitting sounds numerous enough to form a very com- 

 plicated language; and he asserts that he observed they 

 employed some of these signs in circumstances so com- 

 pletely similar, that it cannot be doubted they attach a 

 fixed signification to them. His observations on this 

 head are very interesting, and mast enrich the natural 

 history of such species. 



He also endeavours to prove that the species may per- 

 fect their processes in certain circumstances ; but perhaps 

 naturalists will here discover that he has sometimes mis- 

 taken difierent species for one and the same species in a state 

 of greater perfection. Thus, the architect beaver of Canada 

 is not entirely similar to the terrier castor of the Rhone; and 

 the greo;ariou3 spider of Paraguay is by no means the 

 same with our solitary spiders. 



We may conceive, from what we have mentioned above, 

 that the greatest difficulty for M. Dupont would be, to ex- 

 plain how insects have acquired the precautions, so marvel- 

 lous, with which they prepare for the egg they produce, and 

 for the worm it is about to hatch, the requisite security and 

 nourishment ; although these insects often never saw, or, if 

 €ney did, never will see again, either a similar egg or a si- 

 milar worm ; and although the wants of the worm have no 

 relation with those of the insect which works for it. 



Amonir the multitude of examples which we may adduce, 

 M. Dupont has chosen -one only ; but we do not think he 

 has been happy in his choice; it is that of a false solitarij 

 wasp, the industry of which is as follows : — During its ex- 

 istence as a perfect insect it attaches itself to the flowers ; 

 when it is ready to lay its eggs it digs a cylindrical hole in 

 dayey sand ; it deposits an egg at the bottom : it then goes 

 amonn- some cabbages and seizes upon a small green cater- 

 pillar which it bad never before made its prey; this cater- 

 pillar the wasp nricks with its sling, so as to weaken it, \\\ 

 order that it may not make any resistance against the worm 

 which is about to issue from the egg and- devour it: the ca- 

 terpillar 



