530 DR JAMES W. DAWSON ON 



fibres, both myelin sheaths and axis cylinders, undergoing acute degeneration. Such 

 areas are often accompanied by secondary degeneration, and Redlich thinks that 

 there is no connection between these and those of the first kind. 



In the grey matter are found areas of the first and second types, in which the 

 ganglion cells remain for a long time exempt. 



Huber (1895) also accepts the view of a primary parenchymatous change, i.e. 

 " a simple degenerative decay, not an actual inflammatory decay." 



C. Primary Blood-vessel Alterations. 



This view, stated in simple terms, is that the chief and essential role in the 

 process is ascribed to the changes in the blood-vessels : these give rise to an altered 

 nutrition of the surrounding tissue, leading to degeneration of nerve fibres or to an 

 extension of the inflammatory process to the peri-vascular tissue, with subsequent or 

 simultaneous glia proliferation. 



Rindfleisch (1863) was the first to note the significance of blood-vessel changes 

 in the areas of " grey degeneration," and the intimate relation of these areas to the 

 blood-vessels. It was thought that a chronic irritative condition of the vessel wall 

 introduced the process : that the consequent altered nutrition of the tissue led to 

 changes in the nerve fibres, and, through the extension of the formative irritation, 

 the surrounding glia was involved in a radiating direction. Rindfleisch found the 

 walls of the small arteries and all their delicate ramifications enormously thickened 

 and infiltrated with cells, even in the earliest stages of the process : the walls of the 

 capillaries and veins were also surrounded by numerous nuclei. 



Rindfleisch looked upon the glia as a fused protoplasmic mass with inserted 

 nuclei. He thought that in " grey degeneration " there set in a redivision of the 

 protoplasm around the nuclei, while the periphery of the cell elements, which thus 

 arose, formed into fine fibres. The final result was a feltwork of fine fibres, which is 

 saturated, like a sponge, with a mucoid fluid containing only a few nuclei. He also 

 gave the first accurate description of the large multi-nucleated, ramified glia cells 

 found in the early areas — the so-called spider cells, or monster glia cells, or Deiter 

 cells, or Rindfleisch cells. 



Rindfleisch gave no suggestion as to the nature of the final cause of the 

 postulated alteration of the vessels, nor of the cause of its special distribution. The 

 se< | uenee of the process was as follows : — (l) the change in the vessels; (2) atrophy 

 of the nerve elements from malnutrition ; (3) metamorphosis of the connective 

 tissue (glia). 



RlBBERT (1882) related the areas in disseminated sclerosis to a primary dissemin- 

 ated thrombosis. He described in all the patches a congested vessel, and in several 

 the vessel was so cut that it ran through the whole extent of the area. In two 

 small patches cut in serial sections there were found in the lumen of the vessel white 



