50(3 
David H. DoUcv 
a Statement of the suceessive shifts in the amoiint or distribution of 
chromatin, both intra-nuclear and extra-nuclear, or to put it in more 
significant terms, in the formation and consumptioii of chromatin. In 
the primitive ceU under discussion there are no such extreme shifts to 
deterniine the state of activity. There is no such thing as the disap- 
pearance of the extra-nuclear chromatin at one stage to reappear in the 
next and larger stage, foUowed by its secondary disappearance in a still 
larger cell and final termiuation in the dissolution of the karyosome. 
After a certain point, as the figures bring out, there is a progressive di- 
niinution of the extra-nuclear chromatin, but it is entirely a gradual and 
uniform one, unbroken by abrupt transitions. 
So too at the beginning there is no such distinct, even massive hyper- 
chromatism. However, that a proper differentiation of stain brings out 
something of this is undoubtedly tnie. In the early stages, the cyto- 
plasm may be noted to be not only denser than in the resting type, but 
it is deeper in color than in these within the same section or slide. But 
it is vague as compared with the Purkinje cell, in which not only the 
cell body becomes hyperchromatic but the nucleus as well beconies 
crowded with chromatin at one discrete stage of its activity in addition 
to that nornially alone present in the karyosome. But that there is in 
the crayfish cells what correspoiids to the liyperchromatism in increasc 
of substance and hence a common reaction in this particular, there can 
be no question. Considering the point already made concerning the 
initial enlargement of the cell to double its size or greater, practicaUy 
without edema or indication of disappearance of chromatin, there is 
an absolute increase of formation of materials in comparison with resting 
type ceUs. Again, as the chromatin continues to be produced faster 
than it is consumed for a considerable time, there is in this regard a re- 
lative as well as an absolute hyperchroniatism in comparison with the 
final stages. 
The consumption of chromatin and the edema are accompanied by 
distinct alteration of color. This is more marked in the sensory than 
in the niotor type. From a distinct blue after toluidin blue, the color 
changes in advanced activity to more or less of a violet tinge. As it 
may vary between two cells of the same type and stage, it affords no 
definite eine to the state of activity. 
Tliere are certain other points regarding the nucleolar substance of 
the nucleus and its relation to the extra-nuclear chromatin, which will 
be taken up with the volunie relations as it was the measurements which 
confirmed their apparent existence. 
