THE BACILLUS FOR SMALL ANIMALS 163 



groups, according to their toxicity. Nos. i to 7 may 

 be considered as more or less toxic, and the remainder 

 as comparatively non-toxic. The description given 

 belov^ applies entirely to the intravenous method of 

 inoculation. With Nos. i to 7 there is always a 

 definite rise of temperature to 105° or 106° F. ; it 

 reaches 105° F. twenty-four hours after inoculation, and 

 rises another 0*5° or 1° F. on the following day. On 

 the fourth or fifth day there is a fairly sudden fall, and 

 at the end of the week the normal is again reached. 

 Loss of appetite and consequent wasting are also 

 present, the latter being in most cases very marked. 

 The animals usually die within five to ten days, 

 although they may temporarily recover, and not 

 succumb until two or three months later, while in 

 some cases recovery appears to be permanent. 



From the second to the third day onwards the 

 bacilli are excreted in large numbers by the kidneys, 

 and may be recovered in pure culture from the urine 

 twenty-four hours after inoculation. The kidneys are 

 riddled with nodules after the fifth day, these nodules 

 being formed entirely of lymphocytes, bacilli, and cells 

 of the involved kidney substance. If the animal sur- 

 vives, the bacilli rapidly disappear, and the nodules 

 become absorbed without any caseation. It is worthy 

 of note that in this situation the bacilli attain a great 

 length, and are easily decolorized after staining. 

 Caseous nodules may be found in the lungs, liver, 

 spleen, and peritoneum, and in some cases nodules 

 formed of invading lymphocytes are present in the 

 heart muscle and suprarenal glands. Of the six re- 

 maining bacilli, Duval's so-called leprosy bacillus is 

 the only one that produced a temperature of 105° F., 

 and this result has been obtained in two rabbits. 

 Animals inoculated with these six varieties of bacilli 



