No. 546] INFLUENCE OF STARVATION 319 



experiment is shown by the diagrams. The seriations of 

 number of pods per plant appear in the Data Tables A, 

 B and C. 



TABLE A 



For convenience of reference I designate the 1907, 1908 

 and 1909 cultures the ancestral series and the 1910 crops 

 the comparison series. The fitness of these terms will be 

 apparent. 



C. Experimental Methods and Collection of Data 

 Experimental methods may conveniently be explained 

 under three heads : Selection and Care of Seed, Cultural 

 Conditions, and Collection of Data. 



1. Selection and Care of Seed 

 The necessary requirements are two. First, it is essen- 

 tial that the material subjected to the various environ- 

 mental factors shall be identical in its hereditary tenden- 

 cies. Second, it is essential that in the routine of grow- 

 ing, harvesting and planting no purely physiological (as 

 contrasted with hereditary, germinal or genetic) sources 

 of differentiation shall be introduced. 

 Consider the first requirement. 



We have learned from both biometric and Mendelian 

 researches that it is impossible to know from the simple 

 inspection of an apparently uniform group of individuals 

 whether or not they are really identical as to germinal 

 constitution. It is therefore idle to plant seeds of some 

 individuals under starvation and seeds of other individ- 



