ORIGINATION OF SELF-GENERATING MATTER 283 



the things affecting development especially with regard to the vegetal 

 organism. The first method of multiplication of individuals or 

 colloidal masses undoubtedly consisted of simple fragmentation 

 resulting from the accumulation of a mass too great to be held together 

 by surface tension, and the separation of these masses must have 

 been accomplished, or made possible by flotation which continues 

 to be one of the most efficient agencies in the dissemination of plants, 

 a fact specially emphasized by the results of our studies upon the 

 revegetation of the Salton Basin. 



An early specialization of structure probably rested upon the 

 reduction of portions of the self-renewing colloidal masses from the 

 suspended condition of a sol to the condition of a gel, and doubtless 

 the limiting membranes of protoplasmic masses depend upon this 

 process. Likewise some form of centrum resulted from congelation 

 processes by activities of a nature elementary to the relations of the 

 nucleus and cytoplasm in the modern cell. 



Wherever portions of the colloidal mass came into contact with 

 solid substances gelation or aggregation ensued, and the masses of 

 material thus differentiated would give form and stability in place, 

 representing the earliest form of anchorage organ. In this as well 

 as in other features of the plant, evolutionary development was slow 

 so long as the monotonous conditions of an aquatic habitat were to 

 be met. Very simple processes or extrusions from a cell or coenocyte 

 of this general nature are still to be encountered among certain algae. 



As soon, however, as it was left stranded by the disappearance of 

 the shallow waters in which it may have lived, or was lifted above the 

 water level by any means, the diversified conditions encountered by the 

 organism, including desiccation, exercised a differentiating effect on the 

 root-organ scarcely less marked than those which may be ascribed to 

 the same agency in the shoot. The necessity for anchorage was no 

 less, but now the nutritive substances no longer bathed the entire 

 body but were present only in hygroscopic solutions on the soil 

 particles with a vertical distribution not uniform, and with much 

 horizontal irregularity. Survival depended upon the formation of 

 specialized tracts for absorption, and conduits for the transport of 

 solutions from the organ of fixation to other parts of the living mass. 

 It is to be noted, however, that the modern root arose anew from the 



