1:8 VEGETABLE SUBSTANCES. 



of the wounds of an insect (cynips rosce), resembles 

 no other nidus required for such creatures that we 

 know off; and these red spines on the leaf of the 

 maple are different again from others. It is useless 

 to inquire into causes of which we probably can 

 obtain no certain results ; but, judging' by the effects 

 produced by different agents, we must conclude, 

 that, as particular birds require and fabricate from 

 age to age very different receptacles for their young, 

 and make choice of dissimilar materials, though each 

 species has the same instruments to effect it, where, 

 generally speaking, no sufficient reasons for such 

 variety of forms and texture is obvious ; so is it 

 fitting that insects should be furnished with a variety 

 of powers and means to accomplish their require- 

 ments, having wants more urgent, their nests being 

 at times to be so constructed as to resist the influ- 

 ence of seasons, to contain the young for much 

 longer periods, even occasionally to furnish a supply 

 of food, or be a storehouse to afford it when wanted 

 by the infant brood*." 



Reaumur, the distinguished naturalist, in his Me- 

 moirs on Insects, has a most minute and interesting 

 account of the admirable mechanism by which the 

 genus Cynips (the insect which produces the gall- 

 nut) conducts its remai'kable operations. It is pro- 

 vided with a needle in a sheath, which has most 

 surprising powers of extension, derived from the 

 peculiar construction of the whole body of the insect, 

 so much so that the needle can be extended to double 

 the length of the animal itself; and thus, as we have 

 seen, it forms a nest for its offspring, while the 

 young, in the same manner, pierce their way out of 

 the vegetable shell which has been their protection. 



In Spain, in the southern provinces of France, and 

 along the Mediterranean coasts of Africa, there is 

 * Journal of a Naturalist, page 109. 



