114 TUBERCULOSIS. 



(tubercle of monkeys), or simultaneous consolidation and cheesy 

 deposits (murrain of cattle), or formation of compact tumour 

 masses with imbedded lime concrements (tuberculosis of the 

 hen), &c. But these general apparent differences appear alike 

 on microscopic examination, and the histological structure is in 

 all cases the same." Woodhead, however, goes further into the 

 inquiry and arrives at other conclusions. " Klein," he says, " in 

 a series of experiments reported in 1886, finds that it is possible 

 to inoculate successfully with tubercle taken from tbe human 

 subject ; also that it is possible to inoculate from a guinea pig 

 to a cow, but when inoculation is made from a cow to a fowl 

 the experiment breaks down, and there is no tubercle produced, 

 so that, not only can one modify the activity, and the power 

 of growth of these bacilli outside the body by altering the 

 temperature at which they grow, but it is also within the 

 range of possibility to modify the bacilli by introducing 

 them into different animals whose normal temperatures and 

 other general metabolic conditions are different. This modifi- 

 cation has more than nominal value, for it has been proved 

 experimentally that, although the organisms m human and in 

 bovine tuberculosis are morphologically identical, they are not 

 absolutely the same in all then- vital and pathogenic character- 

 istics. For instance, tubercle bacilli taken from a phthisical 

 patient, and introduced into the tissues of a cow, will soon set up 

 an acute general tuberculosis, whilst bacilli taken from a case of 

 j)erlsu(-lit, or ordinary bovine tuberculosis, almost invariably gave 

 rise to the perlsnrht form of tuberculous disease, and rarely or never 

 to the acute generalised form." On the same subject Bland Sutton 

 says : " In quadrumana and man the disease runsa similar course, 

 whilst in cattle the lesions are so different that it would be diffi- 

 cult to believe that it is in any way related to the tuberculosis of 

 Primates, were it not for the existence of identical micro-organ- 

 isms, and this again applies equally to birds in whom the lesions 

 differ from those in man and cattle." Here I may also quote 

 from Steel, the tliird edition of whose volume, " Diseases of the 

 Ox," was published in 1890 — " Quite recently," he says, " Vir- 

 chow has decided that human tubercle is not the same as the 

 disease in the ox ; and in the Lmirct for lOth June, 1880, Dr. 

 Crei,<diton gives this matter a new aspect by stating that in the 



