OAK APPLES. 35 



and keeping them in a box till they come out. 

 Now there are very many species of gall-flies, 

 but each kind has its own tree, or shrub, or 

 plant in which the eggs are placed. Here, then, 

 we have in this oak gall a most curious and 

 interesting object. It turns out to be an in- 

 habited house provided with food for tiny help- 

 less creatures, that, so far as we can see, serve 

 no useful purpose, and have no great enjoyment 

 of existence. But the fact is that here is a well- 

 devised plan in their interest. The mother, a 

 small four-winged fly, is provided with an egg- 

 depositor and drill combined, most delicate and 

 ingeniously contrived and constructed for its pur- 

 pose. This tool would be of no value without 

 intelligence to use it, and therefore we have in 

 this mere mote, the faculty to distinguish an 

 oak-tree from others, and the skill to get the 

 drill in place and make a proper use of it when 

 there. Shall we go further and say that she 

 knows the eggs she never saw will produce 

 grubs that must have food and shelter ? If she 

 does know that, then is she endowed with some 

 higher faculty than we are ; if she does not, 

 then she is a machine, acting because she must 

 and not because she wills. If we flinch about 

 accepting that view, we are at once driven to 

 the same thing with the oak-tree that becomes 



