THE MORPHOLOGICAL COMPOSITION OF PLANTS. 43 



made familiar to readers of natural history by popularized 

 outlines of The Metamorphosis of Plants — a title, by the 

 way, which is far too extensive; since the phenomena treated 

 of under it, form but a small portion of those it properly 

 includes. 



Passing over certain vague anticipations which have been 

 quoted from ancient writers, and noting only that some 

 clearer recognitions were reached by Joachim Jung, a Ham- 

 burg professor, in the middle of the 17th century; we come 

 to the Theoria Generationis, which Wolff published in 1759, 

 and in which he gives definite forms to the conceptions that 

 have since become current. Specifying the views of Wolff, 

 Dr. Masters writes : — " After speaking of the homologous 

 nature of the leaves, the sepals and petals, an homology 

 consequent on their similarity of structure and identity of 

 origin, he goes on to state that the ' pericarp is manifestly 

 composed of several leaves, as in the calyx, with this differ- 

 ence only, that the leaves which are merely placed in close 

 contact in the calyx, are here united together ' ; a view which 

 he corroborates by referring to the manner in which many 

 capsules open and separate ' into their leaves.' The seeds, 

 too, he looks upon as consisting of leaves in close combina- 

 tion. His reasons for considering the petals and stamens as 

 homologous with leaves, are based upon the same facts as 

 those which led Linnaeus, and, many years afterwards, Goethe, 

 to the same conclusion. ' In a word/ says Wolff, ' we see 

 nothing in the whole plant, whose parts at first sight differ 

 so remarkably from each other, but leaves and stem, to which 

 latter the root is referrible.' " It appears that Wolff, too, 

 enunciated the now-accepted interpretation of compound 

 fruits : basing it on the same evidence as that since assigned. 

 In the essay of Goethe, published thirty years after, these 

 relations among the parts of flowering plants were traced out 

 in greater detail, but not in so radical a way ; for Goethe did 

 not, as did Wolff, verify his hypothesis by dissecting buds in 

 their early stages of development. Goethe appears to have 



