THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 535 



the glia cells and their processes as lymph bodies and canals, i.e. as the roots of the 

 lymph vessels : he believed that in lymph-congestion these lymph-carrying elements 

 swell and finally burst, setting free the lymph in the surrounding tissue. The nerve 

 fibres then degenerate in consequence of the pressure of this congested lymph. 

 Though Arndt's views on the glia texture of the central nervous system have been 

 given up, his view of the influence of the disturbed lymph-circulation on the 

 structural elements of the central nervous system, and especially in relation to " grey 

 degeneration," is very important. 



Schmaus (1901-1905) has also ascribed a considerable significance to the presence 

 of lymph-congestion and oedema in a large number of general diseases, e.g. pernicious 

 anaemia and chronic nephritis. The oedema leads to a dilatation of the meshes formed 

 by the glia, to a swelling of the whole glia tissue, which may advance to such an extent 

 that the fibrils blend to a homogeneous glassy or slightly granular mass, and to the 

 presence of a homogeneous or granular substance in the lymph sheaths of the vessels. 

 The myelin sheaths swell and become varicose, and the axis cylinders are swollen and 

 twisted, on longitudinal section. That these signs are not pre-agonal or agonal is 

 proved by the frequent presence of fat granular cells in the lymph sheaths of the 

 vessels. In such diseases one is inclined to trace the origin of the oedema to toxic 

 substances which circulate in the blood and cause an injury of the vessel wall, which 

 thus becomes permeable to the serous fluid and allows of an increased transudation 

 of (toxic) lymph. 



In disseminated sclerosis Schmaus thinks that the dilatation of the peri- vascular 

 lymph spaces can be explained only by the assumption of a congestion in the lymph 

 stream, which, therefore, distends them. The changes in the blood-vessels, especially 

 the frequently observed adhesions of their lymph sheaths, and the frequent adhesion 

 and thickening of the meninges, lead to this obstruction to the lymph stream. The 

 acute infection which precedes the disease (disseminated sclerosis) gives rise to these 

 chronic inflammatory and proliferative processes in the vessel walls ; these, on the 

 one hand, lead to weakening of the vessel wall and dilatation of its lumen, and on 

 the other hand to condensation and adhesion of its lymph sheaths. Thus is brought 

 about an obstruction to the lymph flowing away, and, in dependence on this lymph 

 stasis, a swelling and degeneration of the nerves fibres in the " Lichtungsbezirke." 

 When the glia in such areas undergoes a compensatory growth, we get the formation 

 of a sclerosed area. Thus a hyperlymphosis may be regarded as the " G-rundlage " 

 of the disease, and this may explain the various types of areas found in disseminated 

 sclerosis. Schmaus thus supports Borst's view of a hyperlymphosis, but attributes 

 to it far less significance than Borst, for he thinks that the constancy of blood-vessel 

 and meningeal changes is by no means proved. 



