CHEMICAL MENDELISM 



quantity of sugar, or of peculiar aroma and taste, 

 or corn containing a considerable quantity of 

 starch, are examples of such sudden chemical 

 variation. Doubtless to these chemical mutations 

 may be assigned all the results which were ob- 

 tained in morphological mutations. But even here 

 it is unknown whether mutations occur in the 

 velocity of reactions or vital processes in single 

 individuals, out of a great number of plants or 

 animals, and whether such variations are well 

 fixed and inheritable. Well worthy of exact 

 examination would be, further, the question how 

 chemical variation works in hybrids. It is well 

 known that the progeny obtained by crossing two 

 species of animals or plants, in many cases follow 

 the rule that only half the progeny remain of 

 hybrid character, but the other half return to the 

 parental types. This law is the famous Mendel's 

 Law. Up to our days we do not know whether 

 chemical characteristics may " mendel " too. 

 It is likely to be so in many cases, and could 

 without difficulty be confirmed at least in a 

 number of experiments. If chemical Mendelism 

 could be discovered, it would be of great interest, 

 because it lies in the nature of Mendelian char- 

 acteristics that they are based on qualities of the 

 nuclei of the sexual cells. 



A further type of variation is known as Atavism. 

 In the formation of a certain characteristic some 

 individuals of the progeny return to the stage 



