THE BACILLUS FOR SMALL ANIMALS 155 



produced by the bacilli never exceeded i° F., and in no 

 case has a maximum of 104° F. been recorded. The 

 normal temperature of a rabbit lies between 100° 

 and 104° F., and, as is well known, slight causes pro- 

 duce considerable variation. Thus a rise of tempera- 

 ture that fails to reach 104*5° F. is not of much 

 significance, except in those animals in which the 

 temperature has been consistently low — i.e., 100° to 

 102° F. before the inoculation. 



Animals receiving a second inoculation usually 

 remain quite healthy, but if a further dose is given five 

 days later, some, after four, five, or six weeks gradually 

 become emaciated, and ultimately die. If a second or 

 third dose is given fifteen to thirty days after the first 

 inoculation, a large proportion of the animals die 

 within four weeks. Here, undoubtedly, one is dealing 

 with animals that have already developed specific 

 anticorps in their blood, etc., and the violent reactions 

 sometimes observed shortly after the second inocula- 

 tion are not dissimilar to ordinary anaphylactic shock, 

 and the ultimate death of the animals is probably due 

 to this cause. 



PosT-MoRTEM Examinations. — A single intravenous 

 injection produces no macroscopic change in any of the 

 organs, with the exception of the kidneys and lungs. 

 Twenty-four hours after the inoculation the kidneys, 

 on histological examination, are found to be congested ; 

 and this condition is more evident in animals killed on 

 the third day. If the animals are killed after three 

 or four weeks, no congestion or other pathological 

 change can be detected. From the first day the lungs 

 are usually somewhat congested, and may show 

 haemorrhagic points, although after a few weeks the 

 normal condition is again found. Animals inoculated 

 intravenously with two or more doses within five days, 



