J. A. Harris 
65 
Summary. 
From the standpoint of genetic or reproductive selection as well as from that of 
general physiology a knowledge of the correlation between somatic characters and 
fertility is of great interest. 
This correlation is not so easily determined on botanical as on zoological 
material, because of the obvious structural interdependence between many vege- 
tative characters and the reproductive organs. 
The involucral whorl of Hibiscus seems a good subject for such an investi- 
gation ; although intimately associated with the fruit there seems to be no reason 
for supposing an important physiological nexus. 
An examination of the fruits of six species of Hibiscus represented by ten series 
of material and involving over sixty-five thousand countings of ovules or seeds or 
both, for individual locules yields statistics which justify the following conclusion 
The correlations between number of bracts and number of ovules or seeds are some- 
times statistically significant with regard to their probable errors but are uniformly 
of such low magnitude that no practical biological importance is to be attached to 
them. 
Cold Spring Harbor, 
Long Island, 
August 23, 1910. 
Biometrika vm 
0 
