THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 539 



diseases, find favourable conditions for development in such parts with local tissue 

 degenerations. These may be the result of capillary bleedings arising from con- 

 cussion and other causes, or local anaemias arising from chill or nervous action (fear), 

 etc. Strahtjber regards the process, on the whole, as an inflammatory one, affecting 

 both the nerve fibre and the glia tissue simultaneously. 



Strahtjber has found sclerotic areas in peripheral nerves, and looks upon these 

 as an expression of the same process. Borst, however, thinks that the investiga- 

 tions were not sufficiently exhaustive, and certainly insufficient to prove Strahtjber's 

 contention that a primary proliferation of the glia is not the essential factor in dis- 

 seminated sclerosis. Muller interprets such areas in the peripheral nerves only in 

 the sense of Gombault's peri-axial neuritis, and thinks that the cases in which they 

 occurred were cases of true acute disseminated myelitis. 



By means of a new staining method for axis cylinders Strahtjber concluded that 

 a regeneration of nerve fibres must take place in the areas of sclerosis. He bases his 

 arguments upon the finding of very fine nerve fibres with very small medullated 

 sheaths and also on the presence of fine naked axis cylinders. These fine nerve 

 fibres, he thinks, are too numerous to be persisting fine axis cylinders, and cannot be 

 compressed nerve fibres, nor terminal stages of a previous swelling, nor primary 

 atrophied nerve fibres. 



Shoyer (1903) notes that a limited number of the patches in the cord in 

 disseminated sclerosis assume certain primary forms, and that the remaining patches 

 can be shown to be due to the coalescence of these primary forms. The primary 

 forms, of which he distinguishes five, are related to the following structural features 

 of the cord : — (l) the posterior fissure ; (2) the anterior fissure ; (3) the central 

 canal ; (4) the points of entry or exit of nerve roots ; (5) a point in each lateral 

 margin of the cord. Shoyer thinks that the shapes of the patches suggest that the 

 changes which form them start in these points to which they are thus related. The 

 oval shape of the first form, the wedge shape of the second and fourth, the circular 

 shape of the third and fifth, all suggest that the active agent enters along the fissures, 

 along the nerve roots, or from the central canal. The distribution of the lesions can, 

 therefore, be explained by the assumption that they are caused by a poisonous agent 

 conveyed by the cerebro-spinal fluid, which finds entry along these roots. 



Tree-gold (1904) has given an account of the microscopical examination of three 

 cases of disseminated sclerosis, each of which was typical of a distinct clinical variety. 

 These were, respectively, the spastic paraplegic, the transverse myelitic, and the 

 cerebellar types. He notes that even in the absence of such symptoms as tremor 

 and nystagmus a careful examination will often reveal some peculiarity in the 

 grouping of motor, sensory, or reflex signs which could only be brought about by 

 disseminated sclerosis. The chief symptoms may, therefore, simulate other diseases, 

 but there are present other signs, not characteristic of such diseases, which could be 

 produced only by disseminated lesions. In each case sclerotic islets were found in 



