4 INTRODUCTION chap, ii 



expresses itself not only in external features (form of the vegetative 

 shoot, and of the leaves, position of the renewal buds, and so forth), 

 but also in the anatomical structure and the behaviour of the plant in 

 life (defoliation, duration of life, and the like). In this regard it is the 

 vegetative organs, especially the vegetative shoots, that are of signifi- 

 cance, whereas in systematic botany it is the floral structure that is of 

 import. The vegetative shoot adapts itself to the conditions prevailing 

 in regard to its nutrition ; but the flower follows other laws, other aims, 

 and particularly adopts very diverse methods of pollination. In the 

 morphology and anatomy of the vegetative shoot are reflected the 

 climatic and assimilating conditions ; whereas floral structure is scarcely 

 or not at all influenced by climate, but preserves the impress of phyletic 

 origin under very different conditions of life. 



An examination of the catalogues or ' systems ' of vegetative forms 

 compiled from time to time will further elucidate the matter. 



Humboldt (1805) was the first to lay stress upon the significance 

 of plant-physiognomy in relation to the landscape : ' Above sixteen 

 different forms of vegetation are principally concerned in determining 

 the aspect or physiognomy of Nature.' ^ He treated the following 

 nineteen forms in greater detail : those corresponding to the palm, 

 banana, malvaceous and bombaceous plants, Mimosa, heath. Cactus, 

 orchid, Casuarina, conifer, Pothos (aroid), liane, aloe, grass, fern, lily, 

 willow, myrtle, melastomaceous plant, laurel. This is, of course, merely 

 a superficial distinction among physiognomic and systematic types ; each 

 of these ' forms ' in reality includes plants with very diverse modes of 

 life. A purely physiognomic system is devoid of scientific significance, 

 which is introduced only when physiognomy is founded upon physio- 

 logical and oecological facts. 



Grisebach ^ made the next important attempt in this direction. 

 He established fifty-four, and subsequently sixty, vegetative forms, 

 arranged in a physiognomic ' system ', and he endeavoured to prove 

 that this demonstrated a connexion between the external form and the 

 environment, in particular the climatic conditions ; according to him 

 a physiognomic type is for the main part also an oecological one. Whilst 

 Grisebach clung in the main to physiognomy and entered into such 

 minutiae as to distinguish, for instance, the laurel-form with stiff, ever- 

 green, undivided, broad leaves, from the olive-form with stiff, evergreen, 

 undivided, narrow leaves, and the liane-form with reticulate-veined leaves, 

 from the rattan-form with parallel-veined leaves ; yet with his sixty 

 forms he distinguished by no means all growth-forms, but rather, as he 

 himself pointed out, only such as could serve to indicate country or 

 chmate by reason of their growing in numbers together. Furthermore, 

 he did not in the least take anatomical structure into consideration, nor 

 did he adequately appreciate epharmony,^ 



In 1884, Warming, having in view the North-European Spermophyta, 

 gave a general survey of growth-forms which he arranged in fourteen 

 chief groups with many sub-groups, based upon morphological and 

 biological characters ; among other characters the vegetative methods 

 of migration occupied a prominent position. Drude, in 1895, justly 



^ Humboldt, 1805, vol. ii, p. 18. * Grisebach, 1872. 



' See Reiter, 1885; Warming, 1908. 



