THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 607 



sclerosis affects the entire transverse section of the cord the area is frequently 

 little more than half the normal. In this very shrunken area impregnation methods 

 show a dense arrangement of the axis cylinders, yet one must admit that many 

 must have perished. 



Numerous writers have claimed that after the degeneration of the axis cylinders 

 there comes a regeneration. Popoff, Marinesco and Minea, and others base their 

 contention on the presence of axis cylinders with a brush-like formation of fine 

 fibres at their end, or on the presence of boules terminates at the end of both 

 terminal and collateral fibres. This possible regeneration has been supported by 

 Schmaus and Huber, and also by Strahuber, on the strength of his aniline-blue 

 staining methods. Bielschowsky, while claiming that most of the fibres in a 

 sclerotic area are " persistent," admits the possibility of a regeneration. Borst, 

 however, who has investigated the regenerative powers of fibres in the brain, and 

 ascribes to them a very considerable regenerative new-formation, thinks that both 

 Bielschowsky's and Strahuber's special methods stain certain kinds of glia fibrils 

 so similar to axis cylinders that it is impossible to draw any conclusion. 



Marburg claims that the first effect of the "toxine" is a lecitholysis : when 

 this effect is carried further or is more intense there is a marked axolysis with the 

 formation of fine granules. But it must be admitted that a change short of this, 

 the demyelination and the swelling of the axis cylinder — which is an indication 

 of its sensitiveness and a proof of its sharing in the changes in the myelin 

 sheath — may be present. 



2. Nerve Cells. 



The relative resistance ascribed to the axis cylinders has also been extended to 

 the ganglion cells, both in the cord and brain. Numerous writers have emphasised 

 their quite normal appearance, both in outer form and minute structure, till a late 

 stage of the process. Catola found normal cells even when sclerosis was com- 

 plete, and Schlagenhatjfer, in a case of disseminated sclerosis which ran its course 

 as a transverse myelitis, found the nerve cells normal at all levels of the cord, 

 even in the most affected segments. 



The relation of the cell changes, when present, to the sclerotic process is difficult 

 to decide, and the majority of the changes should probably be referred to the 

 intercurrent disease, with possible elevation of temperature, which caused death, or 

 to the exhaustion and anaemia and decubitus which accompanied the nervous 

 affection. In judging how seriously diseased a cell is, and specially as to whether 

 it is capable of restoration, the variations in the nucleus have always been counted 

 as affording more useful data than those of the protoplasm. In one case (C. S.), in 

 which every level of the cord showed not only an almost complete demyelination, 

 but cell and glia stains showed that the fat granule cells had been almost completely 

 removed from the tissue, and already an advanced fibril formation was in process, 



