226 Veterinary Medicine. 



tion, capillary clots, minute haemorrhages, and accumulations 

 around the affected capillaries of leucocytes occupying the lymph 

 spaces. Benedikt and Babes attach much importance to the for- 

 mation of hyaline patches in the thickened walls of the vessels 

 and around them, compressing the vessels in some cases to virtual 

 obliteration. The nerve cells Swell up, and show small hyaline 

 bodies in the vicinity of the nuclei, and these latter finally disap- 

 pear. Germano and Capobianco found in addition marked hyper- 

 plasia of the neuroglia. Babes, who looks on these changes as 

 pathognomomic, takes a small portion of spinal cord, hardens it in 

 alcohol for 24 hours, stains it with aniline red and examines for 

 the characteristic hyaline nodes. 



These brain lesions have been found mainly in the medulla near 

 the floor of the fourth ventricle and the respiratory center, but 

 they are also to be found in other parts of the encephalon and 

 spinal cord. The greater constancy of the medullary lesions- 

 serves to explain the characteristic symptoms. 



Histological changes in the Gasserian ganglion of the fifth, 

 nerve, or the flexiform ganglion of the tenth just below the lac- 

 erated foramen give conclusive results in advanced cases. The gang- 

 lion is placed for a few hours in a saturated aqueous solution of mer- 

 curic chloride, then washed- in water, then in alcohol, then 

 mounted in paraffin and sectioned. The sections are stained in 

 Delafield's hsematoxylon solution, and placed under the micro- 

 scope. Normally each nerve cell is enclosed in a capsule, which 

 contains also a single investing layer of endothelial cells. In dogs- 

 dead of rabies, the single layer of endothelial cells is replaced by 

 a great aggregation of cells evidently the result of the prolifera- 

 tion of the single layer. The ganglion cell under their encrease. 

 has atrophied or even completely disappeared. This is met with, 

 throughout the whole ganglion. These lesions are constant in. 

 dogs that have died of the disease, but may be altogether absent, 

 in subjects killed in the early stages. They are best shown in 

 the dog, and less so in man or ox. 



Other lesions are the Negri bodies, cosinophile granules found 

 in the Purkinje cells of the cerebellum and the large ganglion 

 cells of the Cornu Ammonis. These cell- inclusion bodies may be 

 round .5 to 2.3^1, or oblong .5 x 1.5/x or 2.4/*. When fixed in, 

 Zenker's fluid, embedded in paraffin, sectioned, stained 10 to 15. 



