56 
The Ohio Naturalist. 
[Vol. IV, No. 3 , 
THE RELATIONSHIP OF VARIATION TO ENVIRON^ 
MENT IN CHRYSANTHEMUM LEUCANTHEMUM. 
It is not sufficient to show that a particular species possesses a 
•certain index of variability in a restricted locality. We must 
attempt to ascertain the component stimuli forming the environ- 
ment and learn the effect which each group of stimuli has on the 
variability of the organism in question. Onlj’ by so doing can we 
draw accurate conclusions concerning the factors of evolution. 
While natural environment does not furnish us with the best 
conditions for the solution of the problem, a study of the varia- 
bility exhibited by two groups of Clirysantlianuvi Icucanthcmuui 
{the common white daisj’ ) has brought to light some facts of 
considerable interest. 
In a comparison of two groups of 500 each, obtained on the 
same day from localities less than a mile apart, it was found that 
the group having the greater nourishment had the greater varia- 
bility as measured by the “ index of variabilit)- ” 
and the amplitude or range of variation. Thus the data obtained 
in this particular study suggest that the difference in variability 
is dependent on food supply, or, in other words, that chemical 
stimuli are one of the underlying factors producing variability. 
This is a conclusion that has been previous!}’ suggested but not 
definitely established by statistical methods. 
It is evident that there is a need for further investigation in 
this direction on animals as well as plants, for only by the careful 
application of statistical methods can the fundamental principles 
of evolution be ascertained. 
Kenyon College. 
FURTHER FLORISTIC STUDIES IN WEST VIRGINIA. 
An account of a collecting trip through portions of Randolph 
and Webster Counties, especially in the Cheat and Point Mount- 
ains, with brief outline of the more conspicuous and interesting 
fungi — several of which are now reported for the first time. 
L. B. Wai.tox. 
{Abstract.) 
the “ average deviation ” 
W. Kei.lerm.\x. 
{Abstract. ) 
