144 SYMBIOSIS 



following passage abundantly confirms. Thus in the case of 

 Chlamydomonas media, we are told : 



It is possible to maintain the plant, apparently for an indefinite period, 

 in a state of vegetatively active growth. On the other hand, it may with 

 almost equal certainty be compelled to enter on the sexually reproductive 

 phase of its life. A sudden starvation, if previously well nourished, and 

 so long as the organisms are exposed to light, will at once bring about 

 the change that leads to the formation of gametes. But we may at once 

 confess that we do not as yet understand how these conditions work in pro- 

 ducing the observed effects. Nor are we able to form a clear idea as to why 

 the addition of nutritive salts to the water in which the chlamydomonas 

 is living suffices at once to arrest sexual development, and to switch the 

 life processes back on to the vegetative course ; so much so, indeed, that 

 even gametes can develop independently, and in a vegetative manner, 

 i.e., without any sexual union. But the effects of sudden starvation on 

 previously well-nourished organisms are well known to conduce [as long 

 since laid down by Herbert Spencer] to the development of sexual repro- 

 ductive organs. In a chlamydomonas, the organism and the sexual cell 

 are practically identical, and it is in the highest degree suggestive to find 

 that what stimulates the production of sexual organs in a complex and 

 highly differentiated plant, will also cause the undifferentiated primitive 

 one also to enter on a sexual condition or phase. Moreover, the converse 

 is also true, though it is often less easily demonstrated. For a reversal 

 of the conditions that led to the development of the sexual state will 

 arrest it, and cause not only lowly, but many of the higher plants to resume 

 their vegetative growth. Some of the malformations often seen in flower- 

 ing plants, as the consequence of injudicious manuring, represent the 

 results of the antagonism between the sexual and vegetative functions. 

 (Italics mine.) 



And what is it that these typical phenomena are so highly 

 suggestive of ? It is this : that the requirements of inter- 

 dependence are such as to impose upon organisms the necessity 

 of strict limitation of sense gratification contrary to the current 

 idea that all appetites are equally normal and equally sanctioned 

 in Nature. The proviso, " if previously well nourished," signifies 

 that at one time there was an impeding overflow of nutrition, 

 due to indulgence. With a return to a tolerable physiological 

 rectitude of life to symbiotic moderation the sense of proportion 

 reasserts itself, and the organism, duly receiving again support 

 and sanction, progresses along the path of increased individuality 

 and increased biological specialisation. The return of sex proper, 

 with its normal proportions of numbers, coincides in every case 

 with the return of the species from a career of non-symbiotic 

 indulgence to one of symbiotic rectitude. A plant injudiciously 

 manured, is a plant injudiciously fed, and, hence, interfered 

 with in its general integrity, with the result of pathological 



