462 DAVID H. DOLLEY 



other to declare a fixed relation : the most elongated cells, namely, 

 with the longest major axes, are complemented by a similar shape 

 of the nucleus (Experiments Normal 10, Cerebellar Section 4, 

 Shock 36 and 37, and Normal 19); second, the shortest cells 

 are equalized by a comparatively longer transverse diameter 

 (Experiments Muscular Exertion 5 and 3). 



THE MORE EXACT DEFINITION OF THE RESTING CELL RESULTING 

 FROM THE SPECIES IDENTITY 



The resting Purkinje cell is a distinct type, recognizable from 

 its shape, its content and arrangement of substance, its staining 

 reaction, and the absence of certain structural alterations char- 

 acteristic of either activity or depression. It was the last point, 

 of absence of indubitable functional changes, that gave the first 

 morphological clue to its identity. From youth to its prime 

 the contour of cell body and nucleus is even and regular. It 

 shows at most here and there a waviness of outline, but not that 

 crenation and shrinkage which is so prominent in the Hodge 

 stage of activity and which becomes even more pronounced in 

 senility, in short, in temporary and final fatigue. This emphasis 

 of its regularity does not exclude unimportant eccentricities of 

 shape common to all cells of its type whether active or not. The 

 pear-shape may be somewhat attenuated or it may be stout, 

 the long axis may be curved this way or that, or there may be two 

 separate dendrites coming off from the cell body. It is, how- 

 ever, more uniformly regular as a rule than any cell with which 

 it might be confused in diagnosis and more important it shows 

 none of the functional changes of irregularity. 



The nucleus in a youthful or virile animal is packed with 

 nucleolar substance and hence takes a deeper tinge of the acid 

 stain. Its mesh is so close that with the net-knots it has a 

 granular or pebbled surface appearance. It is uniform, without 

 rifts or vacuolation from edema. The abundance of nucleolar 

 substance and the absence of edema distinguish it sharply from 

 the later stages of activity which are characterized by the loss 

 of this substance and the advancing presence of edema. Out- 

 side of the karyosome it has no basichromatin and the presence 



