xviii. SYMBIOGENESIS 



species of organism has a definite bio-dynamic value according 

 to which it affects the organic world for good or for evil, i.e., 

 in the direction of progress or of retrogression. 



Prof. Reichert, of Pennsylvania, in his researches on 

 haemoglobin, has shown that this substance is modified in 

 specific relationship to genus and species. He now extends the 

 hypothesis to the study of starches, expecting to find that the 

 peculiarities of the protoplasm in different species of plants 

 will occasion the formation of different types of starch. " The 

 variations in the starch granule with origin are, of course, well 

 known, and they are of industrial importance." . . "It 

 may be considered as established that starches of different 

 origin vary both visibly and in chemical properties." 

 " It would appear that over and above species variation, 

 differences due to environment and nurture appear in the 

 starches, and it is possible that the further study of such a 

 substance as starch may provide material for the solution of 

 many vexed problems" (Nature, 9/7/14). 



Precisely, and what I maintain is that we are here con- 

 cerned not merely with purely physical or chemical properties, 

 but that it is primarily biological action and reaction (nurture 

 and environment!) which determine, if not the entire composi- 

 tion, yet at any rate the mutual suitability or otherwise of 

 substances for synthetic biological purposes. 



I am providing in the present volume numerous illustra- 

 tions in support of this view ("love-foods" as symbiogenetic 

 substances, alkaloid and albuminoid poisons as pathogenetic 

 substances), and I have also pointed out some striking forms 

 of biological antagonism with which we are becoming 

 increasingly familiar, and which go to show that all life is 

 ruled by great bio-economic principles, the most prominent of 

 which is, according to my view, symbiogenesis. Dr. John 

 Beard has recently shown that the asexual generations of many 

 animals are rapidly killed and digested by pancreatic ferments 

 (Trypsin and Amylopsin), whereas frequently on the other 

 hand the sexual generations are not in the least affected by 



