IN SUSCEPTIBLE ANIMALS. 435 



of other mice which have died as a result of infection. House mice are also 

 susceptible. Rabbits, guineapigs, pigeons, and chickens were found by 

 Loffler not to be susceptible to infection by feeding. 



85. BACILLUS OP CAZAL AND VAILLARD. 



Obtained by Cazal and Vaillard (1891) from cheesy nodules upon the 

 peritoneum and in the pancreas of an individual who died in the hospital 

 at Val de Grace. 



Morphology. Bacilli with rounded ends, but little longer than they are 

 broad ; solitary, in pairs, or in chains of ten to fifteen or more elements. 



Stains with the usual aniline colors, but not by Gram's method ; the 

 extremities of the rods are more deeply stained than the central portion 

 " polar staining." 



Biological Characters. An aerobic and facultative anaerobic, liquefy- 

 ing, motile bacillus. Does not form spores. Grows in the usual culture media 

 at the room temperature more rapidly in the incubating oyen at 37 C. In 

 gelatin stick cultures, at the end of twenty-four hours, a series of puncti- 

 form, white colonies is developed along the line of puncture ; upon the sur- 

 face development is more abundant, and at the end of forty-eight hours 

 liquefaction commences ; this progresses slowly from above downward, 

 and a white, flocculent deposit accumulates at the bottom of the liquefied 



gelatin. Upon the surface of agar, at the end of twenty-four hours at 37 

 ., a moist, transparent, opalescent layer is developed, which rapidly ex- 

 tends over the entire surface ; later this layer becomes somewhat thicker, 

 whitish, and cream- like in consistence, without losing its transparency. 

 Upon potato a thick, prominent, moist, and slightly viscid layer is devel- 

 oped, which at first has a pale-yellow and later a yellowish-brown color. 

 In bouillon development is abundant, producing a milky opacity of the 

 liquid; a thick, flocculent deposit accumulates at the bottom of the tube ; 

 the reaction of the culture liquid becomes very alkaline. All of the cultures 

 give off a peculiar odor, slightly ammoniacal and resembling that of putrid 

 urine. The cultures retain their vitality for several months in a closed 

 tube for more than a year. The thermal death-point is 60 C. with fifteen 

 minutes' exposure. 



Pathogenesis. Pathogenic for rabbits and mice, but not for guinea-pigs. 

 In mice death occurs from general infection, at the end of forty -eight to 

 sixty hours, from the subcutaneous injection of one eighth cubic centimetre 

 of a recent bouillon culture. In rabbits injection of one cubic centimetre 

 into the circulation causes the death of the animal in thirty-six to fifty 

 hours. The symptoms induced are a foetid diarrhoea and paralysis of the 

 extremities. When smaller doses are injected (0.5 cubic centimetre) a 

 chronic malady is developed, characterized at the outset by diarrhoea and 

 emaciation, then by the development of tumors which resemble those found 

 in the man from whom the cultures were first obtained. These tumors are 

 for the most part located in the subcutaneous connective tissue ; after a time 

 they attain the size of a chestnut and ulcerate, allowing the escape of a 

 semi-fluid, purulent material. The animals usually recover. Similar tumors 

 are developed as a result of subcutaneous injections of one to three cubic 

 centimetres of a recent bouillon culture. 



86. BACILLUS OF BABES AND OPRESCU. 



Obtained by Babes and Oprescu (1891) from a case of septicaemia haemor- 

 rhagica presenting some resemblance to exanthematic typhus. 



Morphology. In agar cultures the bacilli are from 0. 4 to 0. 5 ju. thick, and 

 are frequently united in pairs ; associated with these rod -shaped bacteria are 

 forms which are of a short oval. In gelatin cultures oval forms are more 

 numerous ; they have a diameter of 0.3 to 0.4 ju, and often appear to be 

 surrounded by a capsule. In fresh cultures the bacilli are often in form of 



