

INOCULATION OF RABBITS 301 



death may take place in 2 or 3 weeks. The viscera and serous membranes 

 are covered with fine miliary tubercles. 



* 



FIG. 191. The figure represents the lesion produced in a liver of a rabbit 

 3 days after inoculation in the vein of an ear with 1 mg. of finely emulsified 

 culture of mammalian tubercle bacilli and illustrates a typical tubercle, with a 

 peripheral infiltration of small lymphocytes and finely granular oxyphil leuco- 

 cytes, x 600. (Eastwood.) (See footnote p. 295.) 



(b) The Yersin type. Death takes place in 12-25 days. The animal loses 

 flesh and rapidly becomes cachectic. The temperature is very much raised. 

 Post mortem the only visible lesion is a marked hypertrophy of the liver and 

 spleen. There are no visible tubercles. The liver, spleen and bone marrow 

 contain enormous numbers of bacilli. 



Strauss and Gamaleia held that this second (Yersin) type of infection is the 

 characteristic change following mtra-venous inoculation of the bacillus of avian 

 origin, but numerous facts have been brought forward to prove that intra-venous 

 inoculation of the bacillus of human origin may result in this type of infection (Yersin, 

 Nocard, and others). Granchez and Ledoux-Lebard have produced either of these 

 two types of infection at will by regulating the amount of material inoculated. 



Generally speaking, however, intra-venous inoculation of the rabbit with the 

 avian bacillus produces a simple tuberculous infiltration of the organs without any 

 visible lesions. 



[The experiments of the English Commission showed that when death occurred 

 about a fortnight after the inoculation of the avian tubercle bacillus into the veins, 

 disease of the Yersin type is seen post mortem. But if death be postponed to a later 

 period tubercles are visible in the internal organs. 



[When rabbits were inoculated intra-venously with bovine tubercle bacilli they 

 sometimes died within a fortnight of a very acute disease which did not altogether 

 correspond to the Yersin type. In these cases the lungs were solid with masses of 

 grey tubercles, the bronchial glands were cedematous and the spleen enlarged, 

 there were indefinite tuberculous foci in the liver and kidneys, and on microscopical 

 examination tubercle bacilli were found to be numerous in all the tissues of the 

 body. 



[The intra-venous inoculation of human tubercle bacilli will occasionally lead to 

 an acute condition similar to that just described as sometimes following intra- 

 venous inoculation of bovine tubercle bacilli. ] 



