CHAP, iv.] Metamorphosis and of the Spiral Theory. 181 



affinity, saw itself compelled at last to give up the constancy of 

 specific forms in order to make this fact intelligible, and 

 here we see how the idea of the adaptation of organisms is 

 found to conflict with causality, unless we assume that the 

 forms which arise through variation only maintain themselves, 

 if they are sufficiently adapted to the surrounding conditions. 



The movement which began with Goethe and the nature- 

 philosophy assumed a clearer form, found its purest expression, 

 and revealed its most hidden treasures in the writings of 

 Schimper and Alexander Braun ; it would be superfluous to 

 submit to a detailed review the numerous works of less impor- 

 tant representatives of these views. 



We turn from this realm of idealistic philosophy and imagin- 

 ation, from rejuvenescence, the wave-pulse of metamorphosis, 

 the spiral tendency of growth, and the individuality of plants, to 

 the last chapter of our history of systematic botany and mor- 

 phology, where there is less dogmatism and less poetry, but a 

 firmer ground on which will spring an unexpected wealth of 

 new discoveries and of deeper insight into the nature of the 

 vegetable world. 



