SYMBIOSIS 7 



relations it becomes apparent that the ultimate facts of 

 Physiology are also ultimate bio-economic facts. This if, 

 indeed, a comprehensive philosophical view is to prevail in 

 Biology it is vitally important to remember. 



Nutrition entails work and division of labour. " Work," 

 in the proper sense of the word, is therefore the real ultimate 

 fact underlying all " adaptation," as it also, in my opinion, 

 underlies all form. The first and most abiding requirement 

 of the organic world is adequate nutrition, and this has 

 necessitated the constant performance qf work and continuous 

 symbiotic endeavour from the very first. To produce or not 

 to produce, that is the question at every stage of life, even the 

 most incipient. 



Let us see whether this thesis is supported by the results of 

 modern science. First as regards the evidence from Prof. 

 Keeble's work: 



It may be premised that if adult C. roscoffensis are kept in darkness 

 for some time previous to the full development of their eggs, no egg- 

 capsules are laid. The lack of egg-production on the part of dark-kept 

 animals is due to the fact that animals kept under such conditions 

 become starved and, as a consequence, incapable of supplying the eggs 

 with food-materials. 



The starvation in this instance is due to the fact that in 

 the absence of light, the plant partner of Convoluta is unable 

 to do its share of work, and, hence, to co-operate and to provide 

 its usual contribution of food material. The mutual 

 dependence in this instance of symbiosis has become too great 

 to allow the partners to resume independent existence. If 

 Convoluta roscoffensis is robbed altogether of its (" infecting ") 

 green cells, "life is not worth living, and it dies though 

 surrounded by a plentiful micro-flora of which in happier, 

 infected circumstances it avails itself without stint." 



What is it, then, which determines the success or other- 

 wise of the Convolutal adaptation, and which forms " der 

 feste Punkt in der Erscheinungen Fluent " of all 

 adaptation? It is work. Organic life cannot for long 

 afford to be deprived of the possibility of work. 



