268 SYMBIOGENESIS 



Nature a proclivity for experiment-making. Is it not enough 

 that Nature produces soil, seasons and opportunities for pro- 

 gressive adaptations? 



Says Prof. Henslow : 



Thus, if a pond dries up, what will become of the submerged water 

 crowfoot? Will it perish in the changed conditions of air instead of 

 water ? Not at all ! The seeds germinate in the mud, develop the 

 dissected type of leaf characteristic of many submerged plants, but the 

 new plant alters the anatomical structure in order to suit it for an 

 aerial existence, and flourishes even more vigorously than when it was 

 submerged ! 



This is a perfectly good example of self -adaptation ; and, 

 what is more, this plant belonging to the genus Ranunculus, 

 like the frog (rana) from which the name of the genus is 

 derived, the plants being common in the places where frogs 

 abound, is able to make a progressive adaptation from aquatic 

 to terrestrial conditions. 



This is, however, more than many other plants and 

 animals can afford to do, for whether organisms can adapt 

 themselves progressively or not depends on their habits, and 

 adaptation really begins with habits rather than with 

 obvious changes of structure, i.e., with physiological rather 

 than morphological change. The power of adaptation 

 depends on the powers of response and on the kind of biological 

 correspondences established by symbiotic activities. True, 

 seasons are helpful, but only really so to those who remain 

 strenuous, i.e., only with right use; whilst those who abuse 

 seasonal gifts, like the parasites, become highly fastidious and 

 unable to form wholesome or enduring adaptations for lack of 

 correspondences, and also because of atrophy of vital parts. 



Prof. Henslow, however, does not make these vital distinc- 

 tions, and his view, though otherwise to be welcomed as an 

 advanced view, still remains inadequate; lacking, as Prof. 

 Marcus Hartog would say, in "symmetrical completeness." 



The proofs that plants of special " associations" have acquired their 

 adaptive structures by a direct response to the new conditions of life 



