1924 
HARRIS—THE INFLORESCENCE OF MANFREDA VIRGINICA 435 
terms of correlations in the first correlation column of table xv. 
'These coefficients are remarkably uniform from series to series. 
They range from 0.534 + 0.030 to 0.690 + 0.011. These er- 
tremes differ by only 0.156 + 0.032. Іп general the series cannot 
be considered to differ significantly in correlation. 
'The relationship between the number of capsules matured and 
the number of flowers formed is expressed in terms of linear re- · 
gression equations in table хут. 
TABLE XVI 
STRAIGHT LINE EQUATIONS SHOWING THE RELATIONSHIP BETWEEN 
NUMBER OF FRUITS AND FLOWERS PER INFLORESCENCE 
Series Regression equation 
Meramec Highlands 1906 (1) c = — .2113 + .2316 f 
Meramec Highlands 1907 (ТУ) c = —.1139 + .2138 f 
Meramec Highlands 19 с = — .8580 +. 
Мегатес Highlands 1907 (1У) + (V) с = — .2652 + .2216 f 
Jefferson Barracks 1906 (11) с = — .3602 + .2062 f 
Jefferson Barracks 1906 (111) em 5348 + .2382 f 
Jefferson Barracks 1906 (II) + (III) c= 5346 +. 
Jefferson Barracks 1907 (V1) c = + .7869 + .1755 f 
Jefferson Barracks 1907 (VII) с = — .4719 + .2491 f 
Jefferson Barracks 1907 (VI) + (VID с = — 4s 
The slopes of these lines range from + .1755 in the series of 250 
inflorescences taken at Jefferson Barracks in 1907 to + .2491 in 
the large series taken at the same locality in the same year. 
The fact that the widest disagreement is found in 2 series 
from the same habitat and year emphasizes the closeness of agree- 
ment between the results of the several series. ; 
The equations for 2 of the series are represented graphically іп 
fig. 7 for 1906, in which the empirical and theoretical means for 
2 different habitats but for the same year, are laid side by side. 
Two features of these diagrams will at once attract the eye: first, 
the excellent fit of the straight lines to the data; second, the re- 
markable closeness of agreement of the series from the 2 habitats. 
While the correlation coefficients and the regression equations 
showing the relationship between the number of flowers and cap- 
sules per inflorescence have descriptive value, the physiological 
interrelationship between f and c may be best shown by a coef- 
fieient measuring the relationship between the number of flowers 
