BY THE HON. A. NORTON. 113 



meaning of the term." None of these authorities have even 

 hinted that the disease originated with cattle, and was by them 

 transmitted to man in all parts of the " habitable globe " ; nor 

 have any of them suggested that it causes so great a mortality 

 in cattle as that in man spoken of by Fraenkel. In the Austra- 

 lian colonies what is commonly believed to be tuberculosis in 

 cattle has without doubt increased very appreciably in recent 

 years, but it is difficult to believe that the death-rate has 

 yet reached even a third of the " almost one-seventh " which 

 Fraenkel names as the human death rate from this cause. 

 It must not be supposed, however, because bovine tuberculosis 

 has been so commonly referred to, that the ox is the only 

 animal other than man that suffers from the disease. " Among 

 other mammals," says Bland Sutton, " the disease has a peculiar 

 distribution ; it is very common among cattle under the name of 

 grape disease, or its German equivalent, Perlsiicht. Monkeys 

 living in confinement m this country (Great Britain) are 

 occasionally attacked by it, but not so frequently as was formerly 

 supposed. Among grain-eating birds the disease is a perfect 

 scourge." Rabbits, guinea pigs, and field mice, according to 

 Fraenkel, were successfully inoculated by Koch with his artificial 

 tuberculosis cultures. The marmot and a rodent very common 

 in Southern Russia, are also susceptible, the latter, according to 

 Metschnikoff's investigations, exceedingly so. Horses and dogs 

 must also be added to the list ; and two instances of tuberculous 

 snakes have been recorded ! 



Looking at the subject from a general point of view, and 

 having regard only to the results of experiments and observations 

 which have demonstrated the fact that tuberculosis may be trans- 

 mitted from man to cattle and from cattle to man, it might be 

 supposed that the disease is transmissible from any susceptible 

 animal to any other that is susceptible, but this is not the case ; 

 and, even in those cases where transmission is effected, the 

 character of the disease sometimes undergoes very marked 

 changes. Fraenkel refers briefly to these as follows : — " The 

 microscopic picture differs greatly according to the animals 

 infected. We may find an extensive necrosis without actual 

 cheesy degeneration (liver and spleen of guinea pigs), or rapid 

 softening and formation of thin liquid purulent secretion 



H 



