348 DISEASES OF THE RESPIRATORY ORGANS. 



raonic consolidation to conform to the distribution of the 

 smaller bronchi histologically the alveolar exudate resembling 

 that of lobular pneumonia ; in others there is a diffuse hepatiza- 

 tion of one or more entire lobes, the exudate consisting of fibrin, 

 leukocytes, and epithelial cells, as in lobar pneumonia. 



To those cases in which there is extensive pneumonic con- 

 solidation and subsequent caseation and destruction of lung- 

 tissue the term phthisis pulmonalis is often restricted. Origi- 

 nally the term was employed to designate a wasting of the 

 whole body associated with disease of the lungs. The 

 pulmonary lesions, later recognized as characteristic of such 

 cases, were both " ulcerative " and nodular ; gradually, how- 

 ever, smaller nodules tubercles were noted, and finally 

 regarded as the starting-point of the older destructive lesions. 

 In its modern acceptation the term phthisis has come to be 

 used in connection with the wasting or destruction of the lung- 

 tissue rather than with the general wasting and emaciation of 

 the whole body; so w r e find most authors describe separately 

 phthisis pulmonalis and miliary tuberculosis. 



In these bronchogenie forms of pulmonary tuberculosis the 

 factors concerned in the production of a lobular distribution 

 and catarrhal exudation at one time, and a lobar distribution 

 and fibrin cms exudate at another, may not be understood ; the 

 character of the associated secondary infection is, however, 

 quite possibly one explanation. The histological tubercles 

 which are often noted in connection with these pulmonic con- 

 solidations, especially at their borders, might be assumed to 

 be due to the penetration of stray individual organisms between 

 the epithelial cells to the perialveolar and peri bronchial con- 

 nective tissues. These pneumonic consolidations most fre- 

 quently begin in the apices of the lungs, probably as the result 

 of some impairment in the nutrition of the lung-tissue at this 

 point, by reason of lessened aeration of the blood due to 

 diminished range of the respiratory movements at the apices ; 

 general feebleness and cardiac weakness still further favoring 

 the same results. 



It has been stated that when the tubercle bacilli are 

 deposited in small numbers in the pulmonary tissue from the 

 bloodvessels, the lesions are different from those produced by 

 the entrance of large numbers through the respiratory pas- 



