236 SYMBIOGENESIS 



The generalisation that appears most apposite, though 

 it is frequently overlooked, is that there is scarcely any 

 important development in the plant world that has not some 

 reference to the animal as its physiological complement in 

 biological symbiosis; and we may fairly infer that similarly 

 all important developments and susceptibilities that we find in 

 the animal world must have some reference to the connected 

 flora, past or present. 



My view is that these terribly potent vegetable alkaloids 

 are protective in the same way as thorns and other defensive 

 contrivances, and that they tend to restrain the animal from 

 destructive depredation and thus afford a striking case of 

 Nature's safeguarding contrivances calculated to uphold an 

 efficient biological symbiosis, i.e., subservient to symbio- 

 genesis. The measure of their appalling potency is also a 

 measure of the marvellous, though less conspicuous, wholesome 

 properties of plant substances under due relations of symbiosis. 



Again we may thus apply the maxim, Patliologia physio- 

 logiam illustrat. It is quite possible that these vegetable 

 alkaloids are formed from primarily "nutrient materials" or 

 "end-products of metabolism," which but for their diversion 

 for this defensive end would normally go to sustain not only 

 the plant, but also some animal ; they would then be as physio- 

 logically adequate, as they have now, owing to abuse, been 

 rendered not only inadequate, but actually poisonous. Prof. 

 Schaefer likens the effects of hormones to those of the vegetable 

 alkaloids, and Dr. Funk regards the vitamines as the mother- 

 substances of ferments and of hormones, all of which seems to 

 support my proposition. 



It is significant in this connection that sometimes the 

 plant which, by the bye, is the richer and healthier for what 

 is legitimately taken from it seems to divert its poisonous 

 contrivances very evidently against the predaceous animals 

 only, whilst remaining a source of sustenance to the non- 

 predaceous. 



