PRINCIPLES Of veterinary surgery 477 



scopic examinations show aljsolute integrity of all the nerve 

 tissues in one instance and various lesions in others. 



The meninges may be hypercemic and ecchymosed and 

 the medullary substance sometimes presents congestions and 

 haemorrhages. The endyma is thickened with a cellular in- 

 filtration. Rokitansky and Demme have described changes 

 that have no pathological significance (proliferation of 

 neuroglia). Bonhomme mentioned degenerative changes in 

 the white substance of the spinal cord and in the roots of the 

 nerves. Achard has seen degenerated nerve fibres situated 

 in the region of the wound. Nerlich found degeneration in 

 the motor nuclei of the trigemini, the facial and the hypo- 

 glossal. The method of Nissl (1895), so precious in the study 

 of minvite lesions of the nervous system, has recently been 

 applied to investigating the lesions of tetanus, and the most 

 varied results have been obtained. He refers, without de- 

 scribing them, to lesions of the brain cells and their nuclei in 

 tetanized cavies and rabbits. 



Marinesco found lesions in the spinal cords of tetanized 

 cavies which depend upon the activity of the virus and the 

 duration of the intoxication. The gray matter showed dif- 

 fused haemorrhages that are especially numerous in the an- 

 terior (inferior) columns. He observed cellular lesions con- 

 sisting of apparent modifications in the form and volume of 

 the chromatophilous elements. They are smaller and some- 

 times reduced to granulation of irregular form and dissemi- 

 nated through the body of the cell in the appearance of a net- 

 woi^k. In some of the cells they may disappear entirely. The 

 protoplasmic prolongations as well as their chromatophilous 

 elements have an increased volume and their edges are irre- 

 gular and granular. In some cases the cell retains its exter- 

 nal form and is transformed into a homogeneous mass of 

 high color which renders difficult the perception of the 

 •chromatophilous elements. Those observed are profoundly 



