THE MAPLE. 
81 
than merely puncturing 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 like- 
wise 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 excrescence on the wild rose (cynips 
rosae), likewise the result of an insect’s wounds, resem- 
bles 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 re- 
quire and fabricate from age to age very different re- 
ceptacles 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 it is fitting that insects should be furnished with a 
variety of powers and means to accomplish their re- 
quirements, having wants more urgent, their nests be- 
ing at times to be so constructed as to resist the in- 
fluence of seasons, to contain the young for much 
longer periods, even occasionally to furnish a suppy 
of food, or be a storehouse to afford it when wanted by 
the infant brood. 
The wild clematis, or traveller’s-joy (clematis vitalba), 
thrives greatly in some of the dry stony parts of our 
parish, insinuating its roots into the clefts and passages 
of our limestone rocks, where those of many other 
plants could not find admission or support ; and forms 
in our hedge-rows a heavy shapeless mass of runners 
and branches, encumbering and overpowering its neigh- 
bors ; many of which it often destroys ; and we see the 
