108 THE MAPLE. 



a bright red colour, most probably occasioned by 

 the puncture of some insect, though I have never 

 been able to discover any of the larvae inclosed in 

 them. Some insects wound the leaves and sprays 

 of plants for nutriment, though generally the ob- 

 ject seems to be the formation of a nidus for their 

 young, by the fluid that issues from the wound : 

 but insects do something more than merely punc- 

 turing the parts to force a liquor to exude ; a simple 

 wound will not accomplish the desired object, as the 

 sap not only hardens on the surface, but acquires a 

 particular form and consistence, and even at times 

 enlarges to a separate vegetable matter. The insect 

 that wounds the leaf of the oak, and occasions the 

 formation of the gall-nut, and those which are 

 likewise the cause of the apple rising on the sprays 

 of the same tree, and those flower-like leaves on the 

 buds, have performed very different operations, 

 either by the instrument that inflicted the wound, 

 or by the injection of some fluid to influence the 

 action of the parts. That extraordinary hairy ex- 

 crescence on the wild rose (cynips rosae), likewise 

 the result of an insect's wounds, resembles no other 

 nidus required for such creatures that we know of; 

 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 result ; 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 



