66 SYMBIOGENES1S 



are chemotropically attractive substances present which are 

 absent from the latter i.e., the morbidity of the "soil" 

 attracts pathogenic and would-be pathogenic organisms. 



Thus we see that in-feeding organisms have failed to fix 

 upon that course of life which is best in the long run. They 

 are, instead, led away by their bad habits from the good 

 physiological currency, from those (to us) pleasant-tasting and 

 smelling substances in nature which are usually wholesome 

 and rich in adequate bio-chemical potency. They are debarred 

 by their morbid habits from first-hand supplies of vitamines 

 and the virtues of that indispensable medicine of nature 

 supplied by vegetable juices and their ingredients, and conse- 

 quently they develop increasing metabolic abnormalities. An 

 old medical maxim runs: " Pathologia physiologiam 

 illustrat," and, indeed, the above instances of " chemo- 

 tactism " are pregnant object-lessons in pathology. They show 

 how incipient pathology, as I would on symbiotic tests distin- 

 guish it from normal physiology, indeed constitutes a most 

 important chapter of the evolution theory. The point to be 

 insisted upon is this, that no mode of nutrition can be con- 

 sidered normal unless it is associated with an appropriate 

 degree of symbiosis. 



Prof. Keeble puts forward the theory that " the great 

 saprophytic groups of the fungi and the bacteria owe their 

 origin to the changed mode of nutrition imposed upon them 

 by lack of nitrogen." Whatever be the direct or indirect 

 reasons for a change from holophytism to saprophytism, the 

 universal fact remains and that is why I must dissent on 

 general grounds from Prof. Keeble 's explanation of a 

 "nitrogen scarcity " existing in nature that a change from 

 an erstwhile cross-feeding to an in-feeding mode results in 

 pathological developments. " Multo plures satietas quarn 

 fames perdidit viros." What nitrogen scarcity exists must be 

 put down to the prevalence of morbid feeding habits. That, at 

 any rate, such a change involves a deterioration, a loss of 



