THE ORIGIN OF WALNUTS. 171 



a nut rolled into one. In this curious case, 

 the stalk swells out into a bright-coloured 

 and juicy mass, looking something like a 

 pear, but of course containing no seeds ; 

 while the nut grows out from its end, secured 

 from intrusion by a covering with a pungent 

 juice, which burns and blisters the skin at a 

 touch. No animal except man can ever suc- 

 cessfully tackle the cashew-nut itself; but by 

 eating the pear-like stalk other animals ulti- 

 mately aid in distributing the seed. The 

 cashew thus vicariously sacrifices its fruit- 

 stem for the sake of preserving its nut. 



All nature is a continuous game of cross- 

 purposes. Animals perpetually outwit plants, 

 and plants in return once more outwit ani- 

 mals. Or, to drop the metaphor, those ani- 

 mals alone survive which manage to get a 

 living in spite of the protections adopted by 

 plants ; and those plants alone survive whose 

 peculiarities happen successfully to defy the 

 attack of animals. There you have the 

 Darwinian Iliad in a nutshell. 



