LIFE AND MIND 



forces to serve their special ends. One kind of an 

 insect stings a bud or a leaf of the oak, and the tree 

 forthwith grows a solid nutlike protuberance the 

 size of a chestnut, in which the larvae of the insect 

 live and feed and mature. Another insect stings the 

 same leaf and produces the common oak-apple — 

 a smooth, round, green, shell-like body filled with a 

 network of radiating filaments, with the egg and 

 then the grub of the insect at the centre. Still an- 

 other kind of insect stings the oak bud and de- 

 posits its eggs there, and the oak proceeds to grow a 

 large white ball made up of a kind of succulent vege- 

 table wool with red spots evenly distributed over 

 its surface, as if it were some kind of spotted fruit 

 or flower. In June, it is about the size of a small 

 apple. Cut it in half and you find scores of small 

 shell-like growths radiating from the bud-stem, like 

 the seeds of the dandelion, each with a kind of vege- 

 table pappus rising from it, and together making up 

 the ball as the pappus of the dandelion seeds makes 

 up the seed-globe of this plant. It is one of the most 

 singular vegetable products, or vegetable perver- 

 sions, that I know of. A sham fruit filled with sham 

 seeds; each seed-like growth contains a grub, which 

 later in the season pupates and eats its way out, a 

 winged insect. How foreign to anything we know as 

 mechanical or chemical it all is ! — the surprising 

 and incalculable tricks of life ! 

 Yet another kind of insect stings the oak leaf and 



155 



