The icl.itiuli- 111 liiil(irliiil|i||i:i ;iihI iitlirr (■yt(>l)la.stl)i<' cdlist it lli-llts fir. 475 



(if iKitc to IIm' sI iiirt 111 cn (il)scr\ ('(1 l»\ liiiii li;i\c ililìri-cd Irmii tliosf 

 used by ollicrs. mid ;is ;i result svimnv iii> Ihinc acciiiiiiihitrd to an 

 cxtvaordiiiJU'y dc^i'cc KiirtlicriiKirc men li;i\i' Ih-cii foiiteiit -to study 



ill delilil one colisi itileilt ol llie cy I o|)|;i>iii In the lot;il eXeliisimi < d' 



all otlieis. and tri Imild ii|iiiii ilii.v li;ivis tlif^orics of fiiiietioii. The 

 inevitable result is confiisioii. The tendency. ;it pioent. of the nin-.i 

 recent work is eorrelatioii. in\ cstio-atoi's are now woikiii2' with tlie 

 broad biolo^'ieal eoncei»tiuii tliat all c(d!s aie in a >ense fnndaiiientally 

 similar. The immediate outcome is this: that iiiitocliondria are tieino- 

 recorded in all cells from jilants and the lowest protozoa to man. the 

 Nissl substance and the canalicular apparat ii> aiv lieiiii: sliown to be 

 of the most general distribution, and tilnils in epidennnl mid other 

 cells are found to bear an extremely close resemblance to neurotibrils. 



The object of this investigation is to extend this process of cor- 

 I'elation. A single type of tissue has been chosen and to it ]ia\"e 

 been applied as many different forms of recognised, classical, cy tidoaical 

 te('hnique as possible. Many of these methods have never before 

 been applied to nerve cells, while others have been almost exclusively 

 confined to them. In several instances one method has been employed 

 after another to demonstrate the similarity or the dissimilarity of the 

 structures shown by each. Believing that the cell is a harmonious 

 whole and that any attempt to dissociate its constituents is likely to 

 result in error, the general view point of synthesis has been adopted. 

 The term synthesis is here intended to express the successive demon- 

 stration in a single cell of all of its known cytoplasmic constituents, 

 w^hich are present in the living condition although practically invis- 

 ible. This is often accomplished by a[iplying one stain to a cell, 

 fixing it in, adding another and another: or else by staining one com- 

 ponent in a specific fasliion. and tlien dissolviui:- out the dye and 

 staining others in the same cell by appro[iriate methods. All the 

 figtires have been drawn from, and all the desciiiitions ivfer to spinal 

 ganglion cells of the adult ]dgetm. 



Finali}', I which to acknowledge my indebtedness to Professor 

 R. R. Bensley, and to Professor 0. Judson Herrick for many suggestions 

 and for their invaluable criticism. 



