540 
David H. DoUev 
change and upon its charactcr as temporary or permanent that tlie extent 
of recovery depends. Yet in the full tide of its powers, so far as one 
can see, an immediate exhaustion of energy-supplying inaterials affects 
the cell intrinsically but slightly. 
Presenting now more fully the side of the crayfish, there is morc 
of an equilibrium between the formation and the consiunption of chromatin. 
After the readjustment in the homologue of the Hodge stage, both 
plasma and nuclens increase for a long time in very neai'ly the same ratio, 
maintaining a remarkably constant nucleus-plasma relation. This equili- 
briiim probably depends upon certain differences in the processes of 
both formation and consumption. In formation, the intake of the cell 
appears to ba uniform, for the cell steadily increases in size, whüe in 
the Purkinje cell the intake is certainly not continuously uniform, as 
shown by the Hodge stage of shrinkage. Further, there is not the intense 
hyperchromatism of the Purkinje cell, vliich can only be referred to the 
greater labüity or sensitiveness of its nucleus. Though for the crayfish 
cell, if slower, it is more stable. Finally, the nucleus shows less degree 
of strain when it comes to the Hodge stage of shrinkage. 
The difference is more apparent, however, in the process of con- 
sumption. Consumption in the Purkinje cell rapidly nms away from 
the initial over-production as is sho^vn by the fact that from an excess 
the cytoplasmic chromatin dwindles to the vanishing point comparatively 
early. This is not a difference due essentiaUy to deficiency of elaboration, 
for at the Start the Purkinje cell shows the greater facUity in that. Noth- 
ing like this over-consumption occurs in the ceUs of Cambarus. On the 
other hand, it is to be emphasized that probably it is only most tangibly 
a difference of consumption, for the extra-nuclear chromatin is restored 
faster than it is consumed for a long period, since the absolute amount 
evidently increases well toward exhaustion. Taking the series of Fig- 
ures 1 — 7 of the central motor type, the enlai'gement is evidently due 
principally to an increase of substance and in much less degree to the 
edenia. 
Summing them up, the crayfish cell is characterized by a slower, 
more continuous formation of a more stable chromatin as contrasted 
with a more rapid formation of a more shifting and labile chromatin 
in the Purkinje cell. The differences of elaboration ai'e not those of 
method but of degree and of quality of the product. If the supply keeps 
ahead of the deniand more uniformly in the crayfish cell, nevertheless 
there is an extraordinary attempt to accomplish the same thing on the 
part of the mechanisni in the other. 
