Problems of Gametic Constitution 89 



and there must be common concepts, underlying agents and processes, methods 

 of production and evolution or transmutation, that should be conceived of and 

 pondered much ; otherwise, individually or collectively we are soon lost in some 

 intellectual cul-de-sac, from which escape is diiScult. 



In the presentation of the data of this attempt to determine the composition 

 of the gametic material,' I shall present first the results of interspecific crosses, 

 first those of the simplest reactions, later those of more complicated characters ; 

 second, the findings in intraspecific crosses, especially the experiments that have 

 shown the nature of the chromatic determiners and their various capacities for 

 fragmentation ; and at the end attempt a further analysis of the general aspects 

 of the findings and their bearing upon the problems of germ-plasm constitution 

 and architecture. 



* The complete account of the gametic analyses made with these materials is in 

 process of preparation, to be presented in a separate report. 



