PA THOLOG Y OF HYDROPHOBIA. 467 



phobia, of whichever kind, arise, a fatal issue is absolutely 

 certain. 



While a source of infection undoubtedly occurs in all 

 cases of hydrophobia, and can usually be traced, the results 

 of all attempts to determine the morbific cause have been un- 

 satisfactory. Various bacteria have, on insufficient evidence, 

 been described as associated with the disease. Recently, 

 however (1896), Bruschettini, by using media containing 

 lecithin and matters extracted from the brain, claims to have 

 isolated a bacillus which reproduces rabies in animals. The 

 disease presents so many analogies with other conditions 

 arising from bacteria or other micro-organisms, that for this 

 reason alone it requires our attention, and besides, the 

 principles which underly the great work of Pasteur on this 

 subject are essentially those which, applied to diseases un- 

 doubtedly bacterial in origin, have been prolific in results 

 similar to his. 



The Pathology of Hydrophobia. In hydrophobia as 

 in tetanus, to which it bears more than a superficial re- 

 semblance, the appearances presented in the nervous system, 

 to which all the symptoms are naturally referred, are com- 

 paratively unimportant. On naked -eye examination, con- 

 gestions, and, it may be, minute haemorrhages in the central 

 nervous system, are the only features noticeable. Micro- 

 scopically, there have been described in the cells of the 

 anterior cornua of the grey matter in the spinal cord, and 

 also in the nuclei of the cranial nerves, various degenerations. 

 These include pigmentation, atrophy, and vacuolation of 

 the protoplasm, and the occurrence of a deposit of granules in 

 the nucleus. In the white matter, especially in the posterior 

 columns, swelling of the axis cylinders and breaking up of the 

 myeline sheaths have been noted, and similar changes occur 

 also in the spinal nerves, especially of the part of the 

 body through which infection has come. In the nervous 

 system also some have seen minute bodies which they have 

 considered to be cocci, but that they are really such there 

 is no evidence. The changes in the other parts of the 

 body are unimportant. 



