256 
The Ohio Naturalist. 
[Vol. XIV, No. 4, 
The fluctuation I wish to call attention to is of a somewhat 
different character and involves morphological peculiarities of 
form and quality. The common sandbar willow, Salix interior, 
is typically a rather smooth plant with long linear lanceolate 
leaves. For several seasons I have had this plant under considera¬ 
tion at Cedar Point, Ohio, and last summer collected a series of 
forms ranging from the water’s edge on the bay side to the dryest 
sand dunes and blowouts on the lake side. There is a perfect grad¬ 
ation from nearly glabrous plants at the water’s edge to very 
white-hairy individuals in the hot dry sand, and from the long 
linear-lanceolate leaves of the hydrophytic plants to the long oval- 
lanceolate leaves of the individuals growing in the extreme xero- 
phytic conditions. The latter form has been called Salix wheeled, 
being regarded by some as a species and by others as a variety. 
When one compares the two extremes, there is a most striking 
differences—a much greater difference than exists between a 
very larger number of recently manufactured species. Now why 
is there such a gradation from plants growing in one extreme to 
the other? The final answer cannot be given until breeding 
■experiments are carried on. It might be mentioned that carpellate 
plants are more abundant in the wet soil while the dry sand plants 
are nearly all staminate. The observations in the field indicate 
that the individual responds in its growth to its environment. 
Either the same hereditary factors can respond so as to produce 
diverse structures or there are factors latent under one set of con¬ 
ditions and active in another. If a complex hereditary constitu¬ 
tion is involved it should be possible to segregate at least part of 
the factors involved and thus establish distinct, pure varieties 
which would no longer be able to respond in such an extreme 
manner. But if, as is probable in this case, it is merely the response 
of factors to a greater or less degree to environmental causes, 
during growth, than no such segregation could be brought about. 
Whether the one or the other extreme could be established as a 
permanent, hereditary variety would depend on whether it is 
possible to produce hereditary responses of the same nature as 
are shown in the individual response during growth. This is an 
open question far from being settled at the present time. There 
is no object in asserting the one or the other hypothesis. But so 
far we have no direct evidence that the individual response can 
influence the hereditary constitution thru which it acts. It is 
important, however, to recognize the reality of the diversity of 
individual response leading to individual adaptation to the en¬ 
vironment. Some who have speculated along these lines have 
evidently not had a very thoro systematic and morphological 
knowledge of the plants in the field with which they were dealing. 
Date of Publication, February 23, I9U. 
