Growth and variation in maize. 



129 



divergence of the very large and very small plants from the theoretical 

 mean may be due to genotypic differences. If it be assumed that there 

 are several separate hereditary factors influencing growth, then the very 

 large and the very small plants would tend to be more nearly homo- 

 zygous for there conditions, and consequently tend to maintain the same 

 type of growth. Under such conditions these plants would tend to 

 diverge farther from the theoretical mean. 



It is not our intention to discuss the relation of genetic factors 

 to growth at tliis point. This question will be discussed more in detail 

 after other facts have been brought out. It is sufficient to point out 

 here the possibility of such a theory. 



The quintile deviations of plants ending in a given quintile. 



In the preceding section we have discussed the quintile variation 

 of the measurement of plants starting in a given quintile. We shall 

 now consider, but much more briefly, the same kind of data for plants 

 which end in the given quintiles. The fundamental data for this 

 discussion are given in tables 46 to 60 inclusive. These data have 

 been collected and reduced to percentages in tables 10, 11 and 12. 

 These tables correspond in all particulars to tables 7 to 9, which have 

 already been discussed. 



Table 10. 



Series A. 

 Showing the number and percent of the measurements falling 

 in the several quintiles for plants ending in a given quintile. 



Induktive Abstammungs- und Vererbungslehre. XIV, 



