DISEASES OP THE BLOOD. 37 



disorders are due to blood poisons affecting the central 

 nervous system and remarkably nearly identical localities, 

 the irritation seeming to centre in the medulla oblongata, 

 as probably determined by the anatomical and physio- 

 logical relations of the nutrient vessels. Dr. Growers had 

 found in the medulla in hydrophobia not only leucocytes 

 around the blood-vessels but also an infiltration of the 

 tissues with them, forming in places groups which might 

 be termed miliary abscesses. Kolessnikow, of the Veteri- 

 nary Institute of St. Petersburgh, found the small veins 

 distended with white corpuscles, their walls infiltrated 

 with similar elements, and the endothelial cells of the 

 intima of the veins and capillaries proliferating freely, as 

 also did the connective tissue cells of the adventitia. He 

 also found a clear, yellowish, refractive substance between 

 the endothelial cells and adventitia and inner coat, rarely 

 in the lumen. These changes were especially well marked 

 in the parietal and frontal lobes of the cerebral hemi- 

 spheres, but were also found in other parts. Infiltration 

 of the walls of the vessels was especially seen in the 

 medulla oblongata. Changes were noted around the 

 deep-seated origins of the hypoglossal, spinal accessory, 

 and vagus nerves. The spinal canal was usually plugged 

 with a granular mass and surrounded by lymphoid 

 elements. Recent researches show the "leucocytes" or 

 lymphoid cells of these observers to be bacteria. 



Among the other brilliant discoveries made by M. 

 Pasteur recently, has been his observation that rabies 

 may be communicated by inoculation with substance of 

 the cerebral cortex, of the medulla oblongata, and with 

 the cerebro-spinal fluid. By trephining a healthy dog 

 and placing in contact with its brain cerebral tissue from 

 an animal affected with either form of rabies, the disease 

 may be conveyed with certainty m a few days. This 

 method has been applied to rabbits and other harmless 

 animals as a diagnostic means ; Gibier uses fowls, and 

 considers that they recover from the disease spontaneously ; 

 he describes a special bacterium of rabies, but his views 

 have not been accepted by Pasteur. 



