MORBID ANATOMY 3I9 



while here not only the sum total of the changes, bnt also 

 their order of occurrence and mutual interdependence are taken 

 into consideration. 



The morbid process is a parenchj^matous encephalo-mj-el- 

 itis, of which the exact exciting case is as yet unknown. 

 The changes are thus grouped : (i) appearance of nuclear 

 chromatin, peculiar cell division (neuroglia cells and vascular 

 endothelium,) nuclear movements also in nerve cells, diffuse 

 vascular distension and leucocyte infiltration, re\ealing a con- 

 dition of irritation ; (2) swelling, vacuolation, changes of 

 form, granular appearance of nerve cells and neuroglia ; and 

 (3) more advanced changes in the nerve elements. The 

 changes in the first group may be seen as earh- as five days 

 after inoculation. 



In a more recent article by Germano and Capobianco 

 attention is called to the fact that the destruction of some of 

 the nerve cells in rabid animals is not accepted by everybody, 

 but that in their researches they have been able to confirm the 

 statements made bj^ Golgi, that instances of the complete dis- 

 appearance of nerve cells have been observed, while other cells 

 showing fatty degeneration and partial destruction of their 

 entirety represent intermediate stages between the normal cell 

 and its total disappearance. The alteration of the nucleus 

 may precede or follow that of the cell bod\'. 



The nerve fibers, either in the white or gray matter, 

 undergo a certain amount of change. In a longitudinal sec- 

 tion of the my el, especially through the ventro-lateral columns, 

 there are noted marked changes in the axis cylinders. In 

 some cases they appear uniformly swollen for their whole 

 length, while in others there are varicose enlargements. In 

 the swollen portions there were frequently observed small 

 vacuoles which interrupted the continuity of the axis cylinder. 



During the year 1900, the discovery of changes distinctive 

 of rabies was announced by Van Gehucten and Nelis. These 

 changes are found in the peripheral ganglia of the cerebro 

 spinal and sympathetic systems and are especially marked in 

 the plexiform ganglion of the pneumogastric nerve and the 

 gasserian ganglion. Normally these ganglia are composed of 



