414 Ever-sport mg Varieties 



of the degree in which the attribute is trans- 

 mitted. These are by no means parallel, and 

 seem in some sense to be nearly wholly inde- 

 pendent of each other. The fact that the worst 

 atavists may have the highest percentage of 

 varietal units seems to leave no room for an- 

 other explanation. 



Developing this line of thought, we gradually 

 arrive at the conclusion that the visible attribute 

 of a varying individual is perhaps the most un- 

 trustworthy and the most unreliable character 

 for selection, even if it seems in many cases 

 practically to be the only available one. The di- 

 rect determination of the degree of heredity it- 

 self is obviously preferable by far. This degree 

 is expressed by the proportion of its inheritors 

 among the offspring, and this figure therefore 

 should be elevated to the highest rank, as a 

 measure of the hereditary qualities. Hence- 

 forward we will designate it by the name of 

 hereditary percentage. 



In scientific experiments this figure must be 

 determined for every plant of a pedigree-culture 

 singly, and the selection should be founded ex- 

 clusively or at least mainly on it. It is easily 

 seen that this method requires large numbers 

 of individuals to be grown and counted. Some 

 two or three hundred progeny of one plant are 

 needed to give the decisive figure for this one 



