SYMBIOSIS 67 



status, is well emphasised by Prof. Keeble's own remarks on 

 this subject : 



That the fungi are examples of descent by reduction is undisputed. 

 All the evidence points to their derivation from chlorophyll-containing 

 algal ancestors. Having lost their chlorophyll, and, with it, their powers 

 of photosynthesis, they are now condemned to obtain both carbon and 

 nitrogen in the form of organic compounds and hence are compelled, 

 with the bacteria, to play the part of Nature's scavengers. In their 

 quest for food, they settle either on the dead remains of plants or 

 animals, or, invading the living organism, they exchange a saprophytic 

 for a parasitic mode of life. 



The eminent botanist just misses, I believe, the essential 

 pathological and associated bio-economic implications. It 

 need not follow from my view of these matters that we must 

 deny all usefulness to saprophytism, carnivorism, or even to 

 parasitism. They have their use just as disease and death 

 have theirs. They are " ein Teil von jener Kraft die stets das 

 Boese will und doch das Gute schafft." Evil in the end must 

 subserve the good. So far from denying the presence of evil in 

 wild nature as the corollary to Darwin's Natural Selection 

 theory inclines some to do we find it to be widely prevalent : 

 it is a bye-product of the evolutionary process which, however, 

 is ultimately turned to use much in the same way as many bye- 

 products are being turned to use in modern manufactures. 



The degenerate organism, however, serves itself least. 

 The world of strenuous plants can well afford to permit a few 

 groups here and there to retrogress, much the same as the 

 species Chlamydomonadinece, as we saw, can afford to sacrifice 

 a certain number of individuals for the purposes of pseudo- 

 symbiosis. 



For progressive purposes, however, it is only genuine 

 symbiosis and all that it entails in character, in strenuousness, 

 restraint and mutual forbearance that can guarantee a per- 

 manence of happy productiveness. 



In Evolution by Co-operation I have demonstrated that 

 parasitism is a failure because it violates what I conceive to be 

 the fundamental law of co-operation in the biological world, 



F2 



