THE WONDERS OF LIFE 



destruction) is the result of the work done by the plasm, 

 which is the cause of its partial decomposition or break- 

 down. In both respects there is a striking difference 

 between the two great kingdoms of organic nature. The 

 plant kingdom is, on the whole, the agent of assimilation, 

 forming new plasm by synthesis and reduction from 

 inorganic matter. In the animal world, on the contrary, 

 disassimilation preponderates, the plasm received being 

 resolved by oxydation, and the actual energy taken out 

 of it by analysis being converted into heat and motion. 

 Plants are plasmodomous ; animals, plasmophagous. 



Of all the chemical processes the miost important, 

 because the most indispensable, for the origin and 

 maintenance of organic life is the constant reconstruc- 

 tion of plasm. We give it the name of plasmodomism 

 {domeo =. to build up), or carbon-assimilation. Botanists 

 have the habit of late of calling it briefly assimilation, 

 and have thus caused a good deal of misunderstanding. 

 The more common and older meaning of assimilation in 

 animal physiology is, in the widest sense, the intussus- 

 ception and preparation of the food received. But the 

 carbon - assimilation in plants — what I call plasmo- 

 domism — is only the first and original form of plasma- 

 production. It means that the plant is able, under the 

 influence of sunlight, to form carbo-hydrates, and from 

 these new plasm, out of simple inorganic compounds 

 (water, carbonic acid, nitric acid, and ammonia) by 

 synthesis and reduction. The animal is unable to do 

 this. It has to take its plasm in its food from other 

 organisms — plant-eaters directly, and animal-eaters in- 

 directly. We therefore give the title of plasmophagous 

 to these animal "plasma-eaters." In working up the 

 foreign plasm it has eaten, and converting it into its 

 own specific form of plasm, the animal also accomplishes 

 assimilation; but this animal albumin-assimilation is 

 totally different from the vegetal carbon-assimilation. 



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