308 SYMBIOGENESIS 



Nature has supplied an abundance of materials to which these 

 objections do not apply in the shape of "love-foods," which 

 are as ideally useful as these other foods are injurious. 



The poisonous effect of "heterogeneous sera" bears out 

 very strikingly the thesis that a definite kind of food is 

 required by every organism; that is, I submit, food derived 

 in virtue of symbiotic activities. An animal does not (normally) 

 want the life nor the substance of another for its fare. It 

 does not even want the whole of a plant. It only wants parts 

 parts which can be spared by the plant without serious injury, 

 which is a different matter from wholesale depredation. In 

 short, I submit that the above examination of the phenomena 

 and rationale of anaphylaxis again shows us that those 

 substances which the highest symbiotic activity of the plant 

 can produce, and well afford to exchange with the animal, con- 

 stitute the most valuable, the most ideally proportioned foods 

 for the animal, and I regard this as the fundamental principle 

 of scientific nutrition. This truth may be unpopular and 

 unpalatable to many, but my concern is only with genuine 

 science, which is not always the same as "popular" science, 

 and which without bias rests its judgments upon the evidence 

 adduced. 



I hold that what applies to the plant and to the great 

 problem of production by the plant, applies with equal force 

 in the case of man. The case of the plant and of " production 

 in agriculture" is put thus by Mr. A. D. Hall, F.R.S. 

 (Brit. Assoc., Brisbane) : " The desirable method is to keep the 

 plant free from disease by means of a naturally resistant con- 

 stitution, and by establishing healthy conditions of soil and 

 nutrition." (Italics mine.) He also tells us: 



What is needed is not a field experiment merely, but a discussion 

 of a whole system of cultivation on the economic as well as on the 

 scientific side. This suggests the general consideration that economic 

 research in agriculture is still in its infancy. 



With all this I concur ; but I demur to Mr. Hall's attitude 

 that nutrition may not be scientifically studied because our 



