LUTHER BURBANK 
ardently espoused during a period of at least six- 
teen years subsequent to the death of Mendel, 
during which they had no other champion. 
What I have deprecated, however, in recent 
years, is the over-enthusiasm of certain alleged 
followers of Mendel, who have entertained what I 
conceived to be a misapprehension as to the real 
significance of “unit characters”, and who, mis- 
guided by a narrow range of experiments, and 
lacking the breadth of view that comes with wider 
experience, have supposed that all heritable char- 
acters might be classified as fixed and unvarying 
entities that are transmitted in accordance with 
the Mendelian formula. 
Fortunately, a good many former holders of 
this biased and inadequate view have seen its in- 
sufficiency, and already there is a tendency to 
react from it, evidenced in the writings of some of 
the leading Mendelians; and, coupled with this, the 
tendency to take a broader view of heredity and to 
understand that there are countless heritable char- 
acters that do not Mendelize in any tangible or 
demonstrable way; that “unit characters” are 
themselves made up of subordinated characters; 
that new “unit characters” from time to time ap- 
pear, whereas old ones that at one time Mendelized 
are finally so fixed that they blend with the older 
structure of heredity and no longer present the 
[200] 
