J. A. Harrls 
325 
6. The Correlation between the two Placentae of the Fruit. 
The correlations between organs of the two sides are now available for a 
considerable number of bilaterally symmetrical animal organisms but practically 
nothing has as yet been put into print concerning the similarity of the two sides 
of bilaterally symmetrical plant organs. The fruit of Sanguinaria, furnishes a very 
suitable object for the determination of such relationships. 
Since the two placentae are quite undifferentiated tlie correlations may be 
determined from symmetrical tables. Our tables as published have not been 
rendered symmetrical. Anyone who desires may determine the constants from 
them as they stand. I have worked by both methods and find no sensible 
difference in results. The coefficients for symmetrical tables can easily be calculated 
from them by use of proper formulae*. For the constants see Table 15. 
TABLE 15. 
Organic Correlations for Fruits of Sanguinaria. 
Characters of the two PJacentae 
Correlatiou and Probable Error 
1906 
1907 
Difference 
Ovules of "First" Placenta and Ovules of 
"Second" Placenta ... 
Seeds of "First" Placenta and Seeds of 
1 " Second " Placenta 
Aborted Ovules on "First" Placenta and 
Aborted Ovules on " Second " Placenta 
Ovules on " First" Placenta and Seeds Deve- 
loping on " Second " Placenta 
•9239±-0031 
■801 1± -0076 
•6793 ±-0115 
•7356 + -0098 
•8868 ±-0072 
•8443 ±-0097 
■7070 ±-0169 
■7191 ± -0163 
- ^0371 ± ^0078 
+ ^0429f0123 
+ ^0277 ± -0204 
-■0165+ -0193 
The equation of the regression straight line for the relationship for ovules is 
7/ = 1-1384 + -9239 a,'. 
A graphic representation of the slope and the empirical means shows that except 
at the ends, where the observations are few, the observed and the theoretical means 
show a close agreement. We also note : — 
Ovules of first and ovules of second placenta, 
r= -9239 ±-0031, 
ri= -9229 + -0032, 
7;-)- = --0010. 
Seeds of first and seeds of second placenta, 
r= -8014 + ■OOTG, 
7,= ■8015 + -0076, 
r^-r= -0001. 
* See E. Pearl, Biomctrika, Vol. v. pp. 250, 251. 
Biometrika vii 42 
