324 ORIGIN OF MONOCOTYLEDONS [ch. 



suggests as an explanation that Monocotyledons are on the 

 whole a decadent race, of which some branches mav have been 

 driven to an aquatic habitat to escape the severer competition 

 on land. She regards the existence of a large proportion oi small 

 families among the Monocotyledons as suggesting that the 

 modern members of the group are survivals from a period when 

 they were more numerous and widely spread, and she supposes 

 that they have chiefly maintained themselves in such situations 

 as fresh-water areas, in which competition is less keen than 

 under more genial conditions. This view is obviously bound up 

 with the assumption that the adoption of an aquatic life is a 

 device by which a poorly equipped species may escape from 

 the competition of its more favoured compeers^, saving itself 

 from extinction by retirement into a quiet back-water of exist- 

 ence. In other words, water life is regarded as a refuge for the 

 destitute among plants. The present writer, having begun the 

 study of aquatics ten years ago with a full conviction of the 

 truth of this picturesque theory, has gradually and reluctintly 

 been forced to the conclusion that there is no sound evidence 

 in its favour. On the hypothesis in question, water plants are 

 more or less comparable with the remnant of a defeated race 

 among mankind, which preserves its existence bvretreating into 

 some forbidding and inaccessible region, into which its con- 

 querors have little temptation to pursue it. But this analog}^ is 

 probably quite misleading; it would perhaps be more illumin- 

 ating to compare water plants with the pioneers who are to be 

 found leading hard and difficult lives in barbaric regions on the 

 frontiers of civilisation not forced thereto by failure to ' make 

 good' in the excessive competition prevailing in regions more 

 anciently inhabited, but impelled to the frontiersman's life by 

 a natural, inborn affinity for the adventurous conditions which 

 it offers. In the same way, water plants appear to the present 

 writer to have adopted this mode of life, not as a last resource, 

 but because it happened to suit their particular constitution and 



1 Darwin, C. (1859), Goebel, K. (i 891-1893), Hutchinson, J. 

 (19 1 6), etc. 



