240 A Biometrical Study of Conjugation in Paramecium 
TABLE VIII. 
Correlation between Length and Breadth of Body in Paramecium. 
Series 
Group 
Number 
Table 
A 
Non-Conjugauts ... 
Conjugants 
■5890+ -0304 
•2783 ±-0429 
210 
210 
A2 
A 1 
15 
Absolute Difference 
Relative „ 
•3107+ -0526 
52-7% 
— 
— 
G 
)) 
Non-Conjugants ... 
Conjugants 
•6135+ -0296 
•2063f0454 
202 
202 
C2 
CI 
5) 
Absolute Difference 
Relative „ 
•4072 + ^0542 
66-4 7„ 
E 
Non-Conjugants ... 
•6787 ± -0317 
132 
El 
AA 
55 
Conjugants A 
B ... 
•3952 + ^0402 
•3728 ±^0411 
200 
200 
AA 1 
AA 2 
Simpson's 
Non-Conjugants . . . 
•421 ±-055 
100 
The table shows that the organic correlation between length and breadth of 
body in Paramecium is rather high and in all cases positive, or in other words, 
with an increase in length is associated an increase in breadth. If we consider 
for a moment only the non-conjugants, the coefficient is in every case greater 
than "o. This emphasizes the fact, which has been mentioned before, that the 
shape of the body in this infusorian is relatively constant and definite. That 
the coefficients are not, however, unduly high for such an organism is indicated 
by the fact that in material on variation in the flagellate infusorian Ghilomonas 
Paramecium* , the coefficient of correlation of length with breadth is in two 
fairly extensive series almost exactly equal to that found for the non-conjugant 
Paramecia of Series G. In this connection, I think we must conclude that 
Simpson's value for the length-breadth correlation is probably not to be con- 
sidered as typical for normal Paramecia. It is too low, probably due to the fact 
that his individuals were measured shortly after fission had occurred. We have 
what is perhaps a parallel instance in the present series in the very marked 
lowering of the conjugant correlations. I am inclined to think that the typical 
or normal value for the correlation between length and breadth of body in 
Paramecium is not far from '6. 
In order to help to an understanding of the degree of relationship implied 
by correlation coefficients of the magnitude we have found for the length and 
* CI. Biometrika, Vol. v. pp. G4 ct seq. 
