Feb., 1914.] Ecological Varieties Illustrated by Salix Interior. 
255 
measurements it will be seen that the deposit is the same length, 
about twice the width, and one-half the depth of the cut. There¬ 
fore this material will fit in the excavation already described. 
The deposit has been washed clean and stands out in very 
strong contrast with the sod on which it has been laid. An exam¬ 
ination of the material shows igneous, metamorphic, and sedi¬ 
mentary rocks mixed in hopeless confusion. 
The top layers of the Greenfield dolomite were loose and shat¬ 
tered in many places. The force of the water tore away slabs of 
this rock and carried them along with its load of drift. Hence in 
the deposit finely glaciated pieces are to be found. 
From the sketch it can be seen that the deposit extends toward 
the southwest. This results from a gulley running beside the 
railroad track which served to maintain the water volume and 
velocity. 
ECOLOGICAL VARIETIES AS ILLUSTRATED BY SALIX 
INTERIOR. 
John H. Schaffner. 
The recent advances in our knowledge of fluctuations, muta¬ 
tions and Mendelian phenomena of inheritance have given a new 
conception of the nature of a species and its subordinate groups. 
It is perfectly clear to any one who has studied Mendelian phen¬ 
omena that no individual can contain all of the characters present 
in our ordinary species and that no description of a species based 
on a single individual is adequate. The description of a type 
individual is no doubt desirable to fix specific names, but it should 
be regarded as the description of the individual which may or may 
not give a fairly reliable picture of the species to which it belongs. 
The fact of necessary fluctuation is firmly established and it is 
quite evident that no amount of selection of a fluctuating unit will 
advance or degrade the character involved. There are, however, 
fluctuations or adaptations related definitely to the environment 
which still present one of the important and fundamental problems 
of biology. The fluctuation induced by environment may be 
quantitative or qualitative. In mere quantitative fluctuation 
there may develop enormous differences between individuals of 
the same variety or species. For example, in the wild variety 
of the western Helianthus annuus, the mature plant may be 3 
inches high with a single small head at the top or it may be 17 feet 
high with a multitude of branches and heads, with a corresponding 
thickness of stem. In various species of plants belonging to 
different orders, the individual may develop as a tall, strictly erect 
plant in one environment and in another may assume a perfectly 
prostrate, mat form. 
