io THE DARWINIAN THEORY 



denied the possibility of any relation between recent 

 and fossil forms, stating that "the immutability of 

 species is a necessary consequence of the existence 

 of scientific natural history." He formulated the 

 doctrine of Catastrophism, or the periodical annihila- 

 tion of existing animals followed by re-creation in a 

 modified form. The question of the Origin of 

 Species was now becoming a burning one. 



Goethe, 1790, in an "Essay on the Metamorphosis 

 of Plants" showed the principle of fundamental 

 unity, and demonstrated that all parts of a flower are 

 really modified leaves or stem. In the cultivated 

 rose the stamens and pistils are turned into petals, 

 and gardeners find it possible to cultivate a plant so 

 that it shall be all leaves and no flower, or shall 

 have a gorgeous flower while the leaves remain small 

 and insignificant. It is a pleasant reflection to a 

 naturalist that the keenest and brightest intellects of 

 all ages have not been unmindful of the charms of 

 Natural History, and that they have taken delight 

 in, and have themselves made contributions of great 

 value to the subject. It is grateful to acknowledge 

 this indebtedness to men more widely known for 

 their labours in other directions. Aristotle's first 

 classification of animals on scientific principles — viz., 

 into Vertebrates and Invertebrates — holds good to the 

 present day ; he also recognised the true nature of 

 fossils as the remains of formerly living animals. 

 To poets of all ages and every nation we owe many 

 shrewd and accurate observations, especially on the 

 habits of birds and flowers. Goethe was much 

 struck with the power of modification or adaptation, 



