_Morbific Agent._ The actual factor which produces rabies is not certainty known so that we cannot speak of its bacteriology. That it is due to a specific particulate germ is now indisputable. Paul Bert and Nocard filtered the virulent fluid through plaster and found the clear fluid that had passed through non-virulent. Rivolta, Babes, Bouchard and Peuch severally passed a solution of the rabific brain matter through a Chamberland filter and found the clear filtrate harmless. The virulent agent is therefore not a body in solution but a solid (organism) which is held back by the filter. Hallier, Klebs, Galtier, Gibier, Pasteur, Fol, Babes and Dowdeswell have respectively attempted the cultivation and inoculation of organisms found in rabific liquids but none has stood the test of further experiment. Memmo found a blastomyces in the brains of six rabid rabbits and one hydrophobic child. It stains with the aniline dyes but not by Gram’s method; when thrown into the peritoneum of Guinea pigs it produced clonic spasms and death in 24 hours, and in the dog, after an incubation of 8 days caused emaciation, salivation, a disposition to bite, paralysis of the hind limbs and death in 48 hours. Bruschettini using agar or bouillon, containing lecithin or cerebrin and defibrinated dog’s blood, inoculated with pieces of the brain of an inoculated rabbit, obtained in 24 to 36 hours a group of small transparent drop-like colonies at first microscopic, but becoming larger with each new culture on fresh media. These colonies contained a very small, short, thick bacillus, which stains readily in Ziehl’s carbol-fuchsin, and then presents a central clear band giving the appearance of a diploccus. In fluid media spherical forms are produced, but in fresh cultures the diploccus aspect reappears. Injected subdurally in rabbits it gave rise to what appeared to be paralytic rabies and could be inoculated from animal to animal, with similar results. It failed to grow in the usual culture media from which the brain products are absent, thus fulfilling the conditions, of a microbe the point of election of which was the nerve cells. Marx who has sought for Bruschettini’s organism in 60 cases of rabies has only once found anything resembling it and concludes that it was merely a contaminating organism, which caused a paralysis (Centr. f. Bacter. 1896.) _Viability of the poison._ Galtier found that the virulent saliva remained potent for 11 days if preserved from drying. It persists for 3 weeks in the brain and medulla kept at 0° to 12° C., for a month in sealed tubes, or for several months if protected against septic microbes and in contact with carbon dioxide. In water it is preserved for 20 to 38 days so that water soiled with saliva may easily become a means of infection. In graves it has been found virulent as long as 44 days after burial so that in medico-legal cases results may be obtained by exhuming a suspected animal (Galtier).