82 Morphology BOOK i 



It would, however, be altogether inexact to say that these 

 movements of opinion were universal among botanists. 

 The old views were maintained with equal vigour by many 

 of the first rank, and the new considerations advanced by 

 the organographists were carefully examined and discussed, 

 conceptions of them being advanced which harmonized 

 with the older theory. The controversy cannot well be 

 followed in full detail, but the position can be stated as 

 it was left at the end of the century. 



First place here should be given to Naegeli's great work, 

 Die phys.-mech. Abstammungslehre, published in 1884, which 

 contains a most admirable presentation of the subject from 

 this standpoint. For the English reader, however, it was 

 insisted upon by Vines, who may be quoted as a leading 

 exponent of the view, that the standpoint of pure organo- 

 graphy is utterly subversive of morphology, destroying all 

 homologies. He argued that if in the development of the 

 plant a leaf be regarded as merely the expression of a 

 tendency to increase the plant's body, this tendency would 

 have been satisfied by the acquirement of a flat, branched, 

 thallus, and that further progress to such distinct structures 

 as stem and leaf would have been unnecessary. In his 

 view the gradual evolution of stem and leaf from a primitive 

 thallus has essentially nothing to do with the adaptation 

 of the organism to external conditions ; the differentia- 

 tion of the plant body into members is the expression of 

 the inherent tendency of the protoplasm of the living 

 organism to develop into ever more complex ' aggregates ' 

 of members. This was almost the old Wolffian position, 

 but interpreted in the light of the evolutionary spirit which 

 had appeared since Wolff's own time. It gave us the 

 organism endowed with inherent possibilities of variation 

 controlled by being confined to definite lines by the inherent 

 constitution of protoplasm. The ultimate members, root, 

 stem, leaf, may in this view be looked upon as potentially 



