THE KESPIKATORY SYSTEM. 



517 



tuberculosis with other organisms, especially with the Streptococcus and 

 Staphylococcus pyogenes, with Micrococcus lanceolatus, and the influenza 

 bacillus. 



There is reason to believe that in many cases at least the concurrent 

 infection of tuberculous lungs with the Streptococcus pyogenes may be an 

 important factor in the formation of cavities in areas of consolidation 

 already established. ' The pyogenic cocci apparently play an important 

 part in the bronchitis which so often accompanies acute and chronic 

 phthisis. 



Artificial Pulmonary Tuberculosis in Animals. 



Much light may be gained upon the successive steps in the development of the 

 lesions of pulmonary tuberculosis as well as upon the rapidity with which in a suscept- 



FIG. 297.- EXPERIMENTAL TUBERCULOUS IN- 

 FLAMMATION (MILIARY) IN THE L-UNG OF A 



RABBIT. 



The rabbit's lung shows miliary foci of tubercu- 

 lous inflammation, twenty-two days after the in- 

 jection through the trachea of a small quantity of 

 broth culture of the tubercle bacillus. 



FIG. 298. EXPERIMENTAL TUBERCULOUS INFLAM- 

 MATION IN THE LCNG OF A RABBIT. 



Large areas of solidiflcation in the lung twenty- 

 eight days after the injection through the trachea of 

 a considerable quantity of a pure culture of the tu- 

 bercle bacillus. The lesions resemble those of 

 acute phthisis in man. 



ible animal the lesion may develop, by the study of the tuberculosis artificially induced 

 in rabbits with pure cultures. 



1 For bibliography of concurrent infection in tuberculosis see Lartigau's article on the 

 bacteriology, pathology, and etiology of tuberculosis, " Twentieth Century Practice of 

 Medicine," vol. xx. ; also, for special bibliography of concurrent infection in pulmonary 

 tuberculosis, see Marfan, Bouchard and Brissaud's "Traite de Medecine," t. vii., p. 234 



