﻿Harris: Distru 



AND correlation OF SEXES 665 



omists. Any discussion of the differences in the means of the 

 two species would therefore be superfluous. Since the mean 

 numbers are all conspicuously lower in A . proboscideum one would 

 naturally expect the absolute variabilities as measured by the 

 standard deviations to be lower also. The constants show that 

 this is actually the case. The coefficients of variation show that 

 A. proboscideum is also relatively far less variable than A. vulgare. 

 The result is rather surprising in view of the fact that the collections 

 of A . proboscideum were apparently made from a wider range of 

 habitats than those for A . vulgare. 



The coefficients of variation for number of pistillate flowers are 

 in both species conspicuously higher than those for staminate 

 flowers. The interpretation of this result presents considerable 

 difficulty. Variation in both cases is so low that a deviation of 

 a unit is relatively far greater than in the case of the staminate 

 flowers. Thus without a full consideration of the statistical 

 difficulties presented by the case one cannot assert that biolog- 

 ically there is a greater tendency to variability in the number of 

 pistillate than in the number of staminate flowers. 



TABLE II 



Correlation in Inflorescences of A . vulgare 



Pistillate Flowers 



1 X 1 . 



"7" 



~ 



-^VT 



» 



' 



,0 



HHHHH'^I^-'^ 



staminate 



flowers: 



6-IO 



26-30 

 36-40 



56-60 

 Totals 



=L 



z 



- 



"!-- 



i 







i 1 1 ! 1 1 ^ 



The correlation surfaces for the two species are gi\en as 

 Tables II and III. That for A. proboscideum appears in units. 

 For A. vulgare the range of variation in number of staminate 

 flowers is so wide that it has seemed desirable to group in classes 



