GOETHE. 109 
calyx. Thus the most varied structures of plants 
are rendered possible, and he who in his observations 
keeps these laws always before his eyes will derive from 
them great alleviation and advantage.” These few lines 
contain the pith of the doctrine of the Metamorphosis 
of Plants which so greatly agitated his contemporaries 
during the first quarter of this century. The many- 
sidedness of the idea made it inevitable that the 
notion, once grasped, should extend to the remainder 
of the organic world. Before Goethe, no naturalist had 
regarded insects otherwise than as a given sum of indi- 
vidual forms, distinguishable by certain definite charac- 
teristics. Their internal structure had certainly been 
disclosed by some few great men, such as Malpighi, 
Swammerdam and Lyonet, but a real comparison of 
species and genera had never been contemplated ; still 
less an explanation of the body by its parts. This 
Goethe accomplished, and with true genius; for to his 
theory, and with perfect truth, the rings which in the 
insect are ranged from the head to the tail, presented 
themselves, like the vegetal organs, as mere modifications 
of one and thé same rudimentary organ. There, the 
leaf in the abstract, the primordial leaf or plant—here 
the ring. 
With this—it was in 1796, in the discourses on the pro- 
ject of a general introduction to Comparative Anatomy— 
he enunciated a truth which was not recognized till more 
than forty years later, by one of the most distinguished 
zoologists, Milne Edwards, and applied to the’ knowledge 
of the animal world. This is the idea of the develop- 
ment of organic beings by the heterogeneous evolution 
of their fundamentally similar parts. Of this the cater- 
