816 Morphology of the Fruit of Sanguinana Canadensis 
In neither case can the straight line be considered very satisfactory, but at present 
I do not see the advantage of seeking for further regression equations. When 
more biological data are available it may be profitable to go further with the 
statistical analysis. 
TABLE 4. 
Correlation between Length of Peduncle and the Fertility of the 
Fruit in Sanguinaria. 
Eelationship between Length of Stalk and 
Correlation and 
Probable Error 
Ovules on First Placenta 
•313+ -019 
Ovules on Second Placenta 
•321 + -019 
Ovules on First and on Second Placenta 
•31.5 + -019 
Total Ovules per Fruit ... 
•323+ -019 
Seeds on First Placenta 
•341+ -019 
Seeds on Second Placenta ... 
•356 + ^019 
Seeds on First and on Second Placenta 
•348 + ^019 
Total Seeds per Fruit ... ... ... 
•363+ -019 
Aborted Ovules on First Placenta ... 
•039 + ^021 
Aborted Ovules on Second Placenta 
•029 + •021 
Aborted Ovules on First and on Second Placenta... 
•034 + ^021 
Total Aborted Ovules per Fruit ... 
•037 + -021 
TABLE 5. 
Eelationship 
V 
7i-r 
Length and Ovules per Placenta ... 
Length and Seeds per Placenta ... 
•315 + ^019 
•348 ±-019 
•361 + •oig 
•.388 ±^018 
•046 
•040 
These constants show that there is essentially the same degree of inter- 
dependence between the length of the fruit-stalk and the number of ovules 
formed and the number of seeds developing as between the length of the fruit- 
stalk and the length of the fruit. In the case of both ovules and seeds the 
correlation between length of peduncle and the total number per fruit is slightly, 
though not significantly, higher than for the numbers per placenta. 
A question in which the biologist is interested is this : — Is the relationship 
between the length of the peduncle and the number of seeds developing more 
intimate than that between the length of the peduncle and the number of ovules 
formed ? 
Suppose for a moment that the degree of development of the peduncle affords 
some rough measure of the " vigor " of the plant. I think no physiologist can 
