The Morphology of Fimctional Activity in the Ganglion Cells etc. 527 
Frora this point, the nucleiis-plasma relation shows a rising trend 
just as in Text Figure 5 from man. Its slowness indicates that an equi- 
libriiim is well maintained despite the now greater demand of the cyto- 
plasm upon the nucleus. The fluctuations of the curves when its general 
course is considered must be largely due to the insufficient niimber of 
cells to give an exact average. This tendency toward equilibrium is 
the more remarkable in that it holds for much the greater period of 
subsequent activity. Toward the end, the curves take a much sharper 
course upward, which is more noticeable when individual figures are 
examined. This is the indication of approaching exhaustion in the sense 
of faüure of immediate capacity and power of response to present demand. 
In all of the curves it is to be noted that this further upset is not 
only due to the enlargement of the cell body but to a final decrease in 
nuclear size. The presence of such ceUs as the three lai'gest in Table IV, 
the three largest in Table V — the last one, with a nucleus-plasma 
coefficient of 114,4 being illustrated in Figure 7 — and the largest cell 
in Table III are examples sufficieut to prove this. There is no possi- 
bUity of error in the general truth. The nucleus has lost substance and 
is dwindling to complete exhaustion. The finding of such cells prior to 
the extreme limits of the series is important in ex])laining ÜTegularities 
of the tables and figures which are unavoidable. They show that cells 
of the same type, which as already pointed out may vary in original size 
within certain limits, also vary and are limited as to them final capacity 
of enlargement. When the fuU series is scrutinized with this in mind, 
it explains adequately the over-lapping between consecutive groups, 
though from the uniformity of the curves, conformity to the average is 
much more common than departure from it. Again, this final decrease 
in size of the nucleus finds its equivalent in the Purkinje ceU. In some 
measm’ements on the final stages of exhaustion in that cell, the same 
thing was noted, though the observations were not carried far, as the 
dechromatinization of the nucleus is sufficient to show its exhaustion. 
It is extremely valuable in Cambarus, for no cells as yet have been stimu- 
lated to the point of absolute exhaustion and dechromatinization, cha- 
racterized by breaking up of the karyosome and the passing out of its 
chromatin. As to how dose they are to that, the diminution in size 
of the karyosome, represented for every series in Figures 7, 12, 17 and 22, 
is indicative and significant. For the crayfish ceUs, the latest stages 
observed show that the end of immediate capacity is not far off, even 
without the objective finding of the final stage of disintegration of the 
karyosome, so that they have been carried sufficiently far for present 
