THE CAUSES OF THE STRUGGLE. 307 



have flowers so large and seed-vessels so heavy 

 that we wonder how they could have been pro- 

 duced from such a little assemblage of pseudo- 

 bulbs and leaves. Under cultivation many fail 

 they want to blossom but are too weak. And 

 when they do succeed it is often by a last expiring 

 effort they have done their best to keep up the 

 continuity, and then die. In some species of 

 Catasetum there are male and female flowers, quite 

 distinct in appearance the one from the other, and 

 what is most curious, borne on the same plant at 

 different times. It appears as if the orchid is able 

 to choose whichever of these it is strong enough 

 to bring to perfection. The male necessarily 

 requires a less continuous strain as it is saved from 

 the labour of ripening the capsules, which takes 

 several months. When, therefore, the plant is 

 comparatively weak, only male flowers are pro- 

 duced, but when the pseudo-bulbs are plump and 

 strong, females. These and a thousand other 

 examples of choice of means to a particular end, 

 all go to prove that plants, like animals, are by no 

 means wanting in what we have called physical 

 memory and its complement physical reason. 



Given a so-called individual, how does he, with 

 the assistance of a mate, procreate another link in* 

 the chain that is in any way different from them- 



