METAMORPHOSIS IN PLANTS. 87 



suggests a material metamorphosis of one kind of leaf 

 into the other ; for instance, on this view a sepal might be 

 regarded as a metamorphosed foliage-leaf, a petal as a 

 metamorphosed sepal, a stamen as a metamorphosed petal, 

 and so on. The result of this process would be that the 

 foliage-leaf would come to be regarded as the primitive 

 typical form of leaf to which all the others might be traced 

 back ; a view which became discredited in consequence of 

 the extravagant application of it by the school of "natural 

 philosophers " which Goethe's Versiich may be said to 

 have called into existence ; whose members, following in 

 the footsteps of Goethe rather than of Wolff, but without 

 Goethe's genius, speculated instead of observing. Then 

 there is the other answer, the abstract or transcendental 

 answer, that the various forms of leaves are modifications 

 not of any existing form, but of some imaginary typical 

 leaf. It would appear that this latter answer is the one 

 which Goethe offered, though he is not altogether clear on 

 the point. Having, in § 119 of the Versuck, pointed out 

 that all the various organs of the flowering plant may be 

 referred to one, the leaf, he proceeds in § 1 20 as follows : 

 "It is obvious that we ought to have a general term by 

 which to designate the organ which is metamorphosed into 

 so many forms ; for the present we must accustom our- 

 selves to realise that these phenomena take place backwards 

 and forwards. For we can as well say a stamen is a con- 

 tracted petal as we may say of the petal that it is an 

 expanded stamen ; or that a sepal is contracted foliage-leaf, 

 as that a foliage-leaf is an expanded sepal." Evidently, 

 whilst he had arrived at the extension of the term "leaf," 

 he was unable to formulate the intension of the term. 

 What he sought was the morphological concept of the leaf ; 

 and the reason why he failed to form it was that the mor- 

 phological Botany of his time was too superficial and too 

 physiological to admit of such conception. 



But now I must give you some idea of what I mean by 

 a morphological conception of the plant, or of part of it. 

 You may perhaps have noticed that so far I have uniformly 

 spoken of the various parts of plants as "organs," and I 



