SIZE CHANGES IN NERVE CELL BODIES 301 
them; he does not appear to think they need explanation; he 
does not even consider why he finds them with his technic when 
he is so harsh with me about my technic; but he sees them. 
Coming as this confirmation does from a professed critic, with 
the prestige of a great laboratory behind it, it will doubtless 
carry unhoped for weight. The confirmation imposes the greater 
debt in that this arbitrary division of a continuous process was 
carried to a degree which on its face must have appeared suspi- 
cious, though the number was due to the codrdinate inclusion of 
intermediate stages, and the division was a practical one for 
study. 
The effect of varying function between one animal and 
another must be either qualitative or quantitative, granting that 
there is an effect. For the purpose of further analysis of 
Kocher’s findings and conclusions, these possibilities must be con- 
sidered separately, and the question of qualitative differences 
will be taken first. 
His final conclusion which relates to this point is: ‘‘ Further- 
more, no qualitative differences in histological characters could be 
found between fatigue and resting nerve cells.’’ Or, as it reads 
somewhat differently in the text: ‘‘There are neither progres- 
sive changes in the morphology of the cells from rest to exhaus- 
tion, nor are there any qualitative or quantitative differences in 
type of cells from resting and fatigued or even exhausted animals 
(italics mine). Qualitative cellular difference between animals 
in relative degrees of activity is what he wishes to specify, and 
assuredly there is none, if representatives of the thirteen stages, 
in orderly relation, are to be found in all, and only those. But 
Kocher is artlessly misled because he finds all stages in the ‘con- 
trol’ as well as the exercised animal. So his conclusion of lack 
of qualitative difference does not mean what he thinks it does, 
that nothing has happened. On the contrary, it is a fundamen- 
tal conclusion that qualitative differences from function are to 
be ruled out. Instead of being destructive to me, this is the 
first induction I should wish to be confirmed, since it throws 
comparative function on the quantitative principle. It is only 
- that our opinions of the significance of an identical conclusion 
differ. 
