304 DAVID H. DOLLEY 
turb a count quite considerably. What are the characteristics of 
stage 6? Standing at the transition point between the shrunken 
hyperchromatic Hodge stages and the following hypochromatism 
and upset of the nucleus-plasma relation, it has a more swollen, 
vesicular and disproportionate nucleus than the resting type, 
though its plasma now comes to show the average distribution 
of chromatic substance of that type. I have pointed out several 
times that unless its nuclear size and appearance be kept in 
mind, it will be mistaken for a resting cell. 
A second point: Stage 13 is one of complete basic dechro- 
matization. The Nissl substance is gone, likewise the nuclear 
chromatin. The rapidity of such dechromatization depends on 
the relative differentiation. It may appear within a few hours 
in the Purkinje cell, though probably not unless the animal is 
advanced in activity to start with. Not only has it never come 
under my observation in a lower type of cell within the time 
necessary to produce it in the cortex, but the indications have 
always been that the lower cells at this time were many stages 
removed from exhaustion. It was only marked, though still not 
absolute, after two weeks of continuous excitation of the cray- 
fish cell. 
Yet Kocher is extremely liberal with stage 13. He always 
finds it in the cervical and lumbar cord cells, and in two cases 
out of the four animals counted there are more than from the 
cerebellum. Not only do I regard this as impossible on the basis 
of differentiation, but it does not jibe with the text, for he only 
mentions grades of plasmic chromatolysis, which obviously is 
another thing from nuclear plus plasmic dechromatization. 
Nuclear dechromatinization would exact a comment from any one. 
In other words, some at least of the stages identified as exhaus- 
tion are fairly doubtful, and this carries closely related stages. 
One is forced to the same deduction for Kocher’s whole table 3. 
It is the sort of rebuttal of a criticism that personally is very 
distasteful, for it carries the possible imputation that the orig- 
inator of said stages is the only one competent to pass judgment 
upon them. This is not true, for eight students who have 
worked with me have had no difficulty after several months : 
