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 he 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 difterences 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 1 7 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 fonn. 



