504 
David H. Dolley 
size. Outside of that, however, rendering the diagnosis usually easy 
without measurement, are to be mentioned the less dense structure of 
the smaller centro-peripheral cells and consequently their somewhat 
paler color. More characteristic is the much larger size of the intra- 
cellular fibre relative to the size of the cell than in the central type. 
This point holds true throughout activity as reference to the figures 
will prove. 
The sensory resting types without the intracellulai- axone are also 
chiefly distinguished by their different sizes (Figs. 13 and 18). As com- 
pared with the motor types their granulations are larger but less com- 
pactly distributed. In general also their outlines are much more uniform 
though they are not so sharply differentiated from the pericellular sup- 
porting tissue. Within the main group, the two divisions are so far se- 
parated in size that the consideration of the state of actmty of the 
smaller cell when it approaches the resting size of the larger renders the 
diagnosis for the most part easy (compare Figs. 19 and 13). Only 
occasionally did the result of the measurements change the first grouping 
made before the calculations. In staining reaction there is no appreciable 
difference. 
Most helpful in determining the state of activity of any cell is the 
onset and progressive increase of edema in the cytoplasm. It is the 
advance in continuous activity of this edematous condition, so generally 
famüiar to the pathologist, that apparently even more than the con- 
sumption of extra-nuclear chromatin brings about the increasingly less 
dense and paler staining appearance of the ceU body. It is this that 
anatomically speaking is the visible cause of the enlargement of the cell. 
It is first noticeable to the eye in the periphery of the cell, usually before 
there is definite indication of the disappearance of extra-nuclear chromatin, 
though it may be accompanied by that. With the routine stain used 
it begins to appear as rifts and breaks between the cell border and the 
pericellular framework as in Figure 3. This, I take it, is what is ordinarüy 
described for the nerve cell as a pericellular edema or as an enlarge- 
ment of the pericellular lymph space. It is, it is true, a potential lymph 
space and may be so considered within the limits properly requisite for 
that, but it goes so far beyond that it is claimed that it is practically 
and to a large extent inherently intracellidar, for the foUowing reasons. 
With the further progress of activity when the periphery of the cytoplasm 
becomes more and more thinned out and the edematous area wider and 
wider, Strands and fUaments of achromatic reticulum stOl connect the ceU 
substance proper ^vith the original pericellular border (Figs. 12, 17, 19, 20, 
