THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 611 



changes : almost the whole of the protoplasm seems used up and shrivels into an 

 irregular border around the doubly-staining nucleus. In later stages, too, the nuclei 

 may disappear, and thus account for the comparatively few nuclei found as a rule in 

 actual sclerotic areas. 



Weigert's method does not stain the cell body, and therefore his statement as to 

 the spatial separation of the glia fibrils from the cell protoplasm may be overdrawn, 

 but this does not undermine the " Verhalten," the distribution and the specificity of 

 the fibrils, and the fact that they stain at a certain definite stage of their develop- 

 ment. Fieandt's recent work has seemed to support the Hardesty-Held conception 

 of the syncytial structure of the glia tissue. Held believes that the glia represents 

 a widely-ramified but connected syncytial meslnvork of protoplasmic character, 

 which envelops the functioning elements of the central nervous system. At its 

 nodal points are nuclei, and within the protoplasm, not separated from it, are 

 Weigert's specific fibrils. The glia, therefore, represents a continuous reticulum, 

 which holds together the ganglion cells and nerve fibres, and the differentiated 

 fibrils are deposited in this as supporting or stiffening elements. By Nissl's stain 

 the cell nucleus and protoplasm immediately surrounding it are stained, and the cell 

 protoplasm gradually merges in a surrounding meshwork. The sharp concave edges 

 of the bodies are formed by light, strongly refractive lines, which consist of -fibrils 

 that do not stain with basic aniline dyes. Fieandt thinks that glia granules — 

 gliosomes — play an important role in the new formation of glia fibrils, and that they 

 may be looked upon as an intermediate stage between the undifferentiated proto- 

 plasm and the specific fibres. In specimens fixed in Heidenhain's sublimat-trichlor- 

 acetic acid mixture, and stained by iron-hsematoxylin, granules were present, 

 arranged in rows, in the large star-shaped glia cell processes and in different parts 

 of the cell body. In some cases rows of granules are seen to radiate towards the 

 centre of the cell, thus giving the cytoplasm a radial structure. These granules are 

 very fine, and similar granules may be distinguished in the fine meshes of the glia, 

 arranged almost in streptococci-like rows. 



The Hardesty-Held conception of the syncytial structure of the glia tissue would 

 reconcile Weigert's teaching with that of his opponents, and show that in the 

 neuroglia tissue cells — nuclei and protoplasm and protoplasmic processes — 

 differentiated fibres, whether anatomically independent or not, and, finally, inter- 

 cellular protoplasmic fibreless glia, may all exist together. 



In the grey matter of the brain the ganglion cells and fibres are embedded in a 

 tissue which shows a uniform finely granular structure. This is probably constituted 

 by the dendrites and axis cylinder processes of the ganglion cells ; the axis cylinder 

 ramifications from other parts of the grey matter ; the fine intercellular fibril lattice 

 work originating from both ; and by the diffuse protoplasmic glia meshwork with 

 its specific glia fibrils. In this glia meshwork nuclei are fairly evenly distributed, 

 and are specially met with in close relation to the larger ganglion cells — the so- 



