474 DAVID H. DOLLEY 



of the other side, one is compelled to substitute on the side of 

 declination of curve the actually estimated area of the basal 

 bounding plane for the other and smaller bounding plane which 

 is the proper one (refer to fig. 5). For the mesial layers, with 

 their lesser curvature of edge, this is negligible, but it becomes 

 of increasing importance with the increase of slope and especially 

 in the last section layer which presumably is conical in shape. 



It is plain that considerable variation would be expected in the 

 two micra serials. 



4. In fixation and staining 



All the material was fixed in formalin-sublimate (95 parts 

 of saturated sublimate to 5 parts of 40 per cent formaldehyde) 

 and stained in erythrosin and toluidin blue. It is believed that 

 the constancy and uniformity of the results will go far in dis- 

 pelling the bug-a-boo of lack of confidence in technic which has 

 been one of the greatest handicaps to nerve cell study. The 

 fixing fluid was made up as needed, and some of the material 

 had been in paraffin for three years or more. The stain is only a 

 convenient and simple modification of the old eosin and methylene 

 blue combination. In short, it is as much true for the nerve 

 cell as for any cell that the prerequisite is a good fixation, after 

 which any stain proper to that fixation will take. Delafield's 

 hematoxylin stains Nissl substance beautifully when used on 

 properly fixed material ('13 b). After chance for all the contin- 

 gencies that happen in ordinary laboratory management, the 

 constant relation of cell to nucleus emerges essentially undis- 

 turbed. Why should not one expect as much from any other 

 accepted fixative? The actual coefficient figure might or might 

 not be difl'erent from that after mercury, it might be the same 

 for the resting cell and differ in the very edematous exhausted 

 cell ('10), but the point is that for that fixative it should be a 

 constant between corresponding cells, and hence perfectly 

 reliable. Yet the tendency has been to lay everything at the 

 door of technic. Variations in size, irregularities of shape, 

 even variations in chromatin are primarily ascribed to fixation 

 and stain. Differences in technic do cause certain alterations 



