164 Manual of Veterinary Microbiology.. 



than those in the vicinity of the margin of the cover 

 glass where they are killed by contact with the air. 



Experimental inoculations. — The species endowed 

 vvdth receptivity for the bacillus of gangrenous sep- 

 ticffimia are : guinea pig, rabbit, sheep, goat, horse; then 

 in the order of decreasing affinity, the ass, chicken, 

 pigeon, and, finally, the dog and cat. Cattle are abso- 

 lutely refractory ; this is a remarkable exception which, 

 itself, is sufficient to differentiate this pathogenic 

 agent from that of sym[itomatic charbon, with which 

 is has several points of resemblance. 



Inoculation is most successful when made in the 

 subcutaneous cellular tissue (one-fifth of a drop to 

 five drops of the virulent serosity are sufficient) ; it 

 invariably fails when made with the lancet or by su- 

 perficial scarifications. When injected into the cir- 

 culation the animal can tolerate doses much larger 

 than those which prove fatal when injected into the 

 subcutaneous cellular tissue. Subjects inoculated in 

 this way suffer from a fever of more or less intensity 

 and obtain immunity ; but, when the quantity intro- 

 duced into the blood has surpassed one to three drops 

 of the virulent serosity in the rabbit, one to five cubic 

 centimeters in the sheep, ten to thirty-five cubic centi- 

 meters in the ass, it leads to the death of the inocu- 

 lated subject. In animals which have been rendered 

 refractory by intra-vascular injection later inocula- 

 tion in the connective tissue produces a slight swell- 

 ing or, at most, the formation of a curable abscess. 



The serosity taken from the muscular tissue, the 

 connective tissue, and the parenchymatous oi'gans, is 

 more virulent than that from the serous cavities. 



Inoculation in the connective tissue is followed by 



