EXPERIMENTS WITH INFECTED MATERIAL 143 



Udder inoculated into two guinea-pigs intravenously, one nega- 

 tive in two months, one died in two days. 



Lymph glands of pleura inoculated subcutaneously into two 

 guinea-pigs, negative in two months. 



Although in the naturally infected cow the bacilli 

 were particularly numerous in the caecum, it is 

 interesting to note that all the inoculations, even in 

 the calves and in the goat, gave negative results. 



These authors, however, made similar experiments 

 with seven other cows which showed lesions of Johne's 

 disease ; five of these were also tubercular. In some 

 cases the small animals inoculated with infective 

 material from those cows, which were tubercular, 

 contracted tuberculosis ; but, although a very large 

 number of animals (including a sheep) were inoculated 

 by various channels with infected intestine, Miessner 

 and Trapp were unable to reproduce the disease in 

 any species with the exception of three calves. Of 

 these calves one was inoculated intravenously with 

 mesenteric gland, and the remaining two with the 

 intestinal mucous membrane of a cow suffering from 

 Johne's disease. In these cases the disease was demon- 

 strated on post-mortem examination. In each case the 

 intestine was thickened, and films from the thickened 

 portions showed numerous acid-fast bacilli. With the 

 intestinal mucosa of one of these calves two more calves 

 were fed and another inoculated subcutaneously. All 

 three animals reacted to avian tuberculin five or six 

 months later (see p. 114). 



Working in 1907, M'Fadyean failed to produce any 

 lesions in rabbits and guinea-pigs by inoculating the 

 animals with infected intestine, and many other authors 

 (Lienaux, Matthis, Freger) have made similar un- 

 successful attempts to infect the small laboratory 

 animals. In other cases tuberculosis has resulted. 



