CHEMICAL ADAPTATION 



morphological characteristics and variations. The 

 oil-seeds of the plants of the flora of our country 

 always contain fat which is liquid at temperatures 

 of above 10 to 20 degrees Celsius, and becomes solid 

 at a few degrees above zero. Tropical plants very 

 frequently contain fat which melts only at a 

 temperature above 30 degrees, and is solid at an 

 average European temperature. This difference 

 is likely to be connected with the temperature 

 in which the plants live. Another phenomenon 

 of the same kind is the rule in the production of 

 enzymes. In moulds no amylolytic enzyme is 

 produced unless these fungi grow on culture 

 medium containing starch, and the common grey- 

 green mould Penicillium glaucum produces an 

 enzyme which destroys wood-substance, when it 

 grows upon wood, but never when it grows on 

 other substrata. For the formative action of 

 chemical and physical influences on the morpho- 

 logical qualities of organisms the term Morphoses 

 has been introduced. In an analogous manner 

 we can name the chemical alterations provoked 

 by these influences in plants and animals Chemoses. 

 Morphoses are to be considered as reactions of the 

 living organism to external stimuli. They belong 

 to the physiology of stimuli, and we cannot but 

 assume that they differ from tropisms and other 

 primitive forms of reactions only in their com- 

 plexity. Chemoses must be considered as reactions 

 of the living organism in the same way, and all 

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