Caryophyllaceæ. 275 



ships, but it will be difficult or rather impossible to demon- 

 strate the origin or utility of their genetic peculiarities (for 

 instance, why the leaves in the Caryophyllaceæ are opposite; 

 the origin of the peculiar manner of branching with only 

 one shoot, or at all events only one vigorous shoot, from 

 each pair of leaves, and of the position of these shoots in a 

 peculiar spiral; or the origin of the one-layered sheath, 

 around the vascular bundle, just mentioned). As regards 

 the Caryophyllaceæ Vesque (1883, p. 133) has rightly stated 

 that "La famille des Caryophyllées est des plus naturelles 

 et des mieux limitées". This is true both as regards the 

 morphological and the anatomical structure and, as far as 

 I can see, cannot be explained ecologically. Also as regards 

 the structure of the flowers, there are very great similiarities 

 in the different genera. 



In the second place, the peculiarities of plants are 

 dependent upon the ecological factors of the habitat, i. e. 

 the climatic and edaphic conditions which prevail there. 

 It is consequently of importance that we should be accu- 

 rately informed with regard to these points, but the truth 

 is, we have information only about the general features 

 of the climate and — possibly — of the soil. As regards 

 the conditions which prevail in the special, local habitats 

 in which the different individuals have been gathered we 

 are, so to speak, never told anything. Unfortunately, there 

 are many travelling botanists who find it sufficient to state, 

 that such and such species have been found here and there, 

 and to record the geographical situation; but as regards 

 the conditions found to be prevailing in the habitats in ques- 

 tion, they tell us nothing whatever. This is however a great 

 drawback, for without doubt the ecological factors, or the dif- 

 ferences which prevail in the habitats, are exactly that which 

 sets a different stamp upon individuals of the same species. 



