962 



number of ganglion cells exceeds the nnml)er of axons and tliat this 

 excess must have some significance. 



From the silver-impregnated series we obtain an indication of (he 

 purpose of this excess in the number of cells. We find that, however 

 intensively the spinal ganglia are impregnated — especially in young 

 animals — there are, all the same, a numl)er of cells that cannot 

 be impregnated, in spite of the fact that the adjacent cells show the 

 most splendid neiiro-fibril structures. It is. however, not always the 

 smallest cells that cannot be impregnated, but a number of average- 

 sized ones as well, while others of the smallest and the average- 

 sized ones show exceedingly fine impregnation. The cpiestion why 

 this or that cell is not impregnated naturally arises. This is by no 

 means the first time that attention has been drawn to the different 

 powers for intensive impregnation shown by the spinal ganglion-cells. 

 Even in his work on "Zell substanz, Kern und Zellteilung" and in 

 the presentation volume to Hknle, Fi-emming points out that cells 

 are stained to different degrees of intensity by the same colouring 

 matter, and is of the opinion that this is (\ne to greater or less 

 density in the colourable fibi-es of which the protoplasm is constituted. 

 Flesch, GiTiss, KoTLAKEvsKY, KoNEFF and Müi-LER ') and others have 

 dealt with this subject more oi less thoroughly. Flesch and his 

 pupils, and Muller among others, have studied the capacity for 

 staining possessed by the ganglion cells. Koneff states that the 

 different capacities for staining are tiot connected with certain species 

 or cells with special morphological characteristics. The cells are large 

 and small, of different shapes, and some of them are distinguished 

 by their chromatic nucleus. For the two kinds of cells — the 

 strongly and the weakly stained — this author suggests the names 

 of chromophila and chromophoba ganglion cells. The author supposes 

 that some of these different cells are in different functional stages 

 and others are developed to different degrees. Muller distinguishes 

 a type of spinal ganglion cells that have, among other characteristics, 

 strongly eosinophile protoplasm and nuclei rich in chromatin; these 

 cells he takes to be developing forms. It is thus not only in silver 

 impregnation, but also with ordinary nuclei and protoplasmic 

 impregnations that this different intensity in the impregnation appears. 

 With regard to these conditions in the BiELscHowsKY-preparation, they 

 indicate to some extent, as has been mentioned, cells with elective 

 neurofibril impregnations and to some extent cells in which no neurofibril 



') Muller, Erik: Studiën über die Spinalganglien. Bioiog. förening. förhandl. 

 Bd. 1. 1888 — 89. Stockholm. Other statements in the literatuie thai touch on this 

 subject are referred to here. 



