142 Dr. E. Klein on the Anatomy of [Jan. 29, 



interalveolar tissue ; in the early stages of artificial tuberculosis, only the 

 perivascular lymphangial cords are to be met with. 



If the infection has been established from the pleural cavity, the ger- 

 mination of the endothelium of the surface round the stomata, and the 

 transformation of the subpleural lymphatics into cords of adenoid tissue, 

 is the first symptom, and is followed by the appearance of perivascular 

 adenoid cords. If, however, the lung becomes tuberculous by infection 

 from the blood-vessels, the peritoneal cavity or the subcutaneous tissue, 

 the perivascular adenoid cords are the first structures that make their ap- 

 pearance. In lungs which have become the seat of chronic pyaemia, the 

 first changes are to be found in the alveolar septa and alveoli, viz. the 

 formation of patches and nodules similar to those that I have designated 

 before as secondary ; and if the process lasts long enough, those 

 changes take place that I have designated before as primary tuberculous 

 changes. 



The opinion has been expressed (by Sanderson and Wilson Fox) that 

 the process of artificial tuberculosis in the lungs of guineapigs resembles, 

 in its anatomical features, the tuberculous process in man. I will 

 therefore examine the process that is clinically and anatomically known 

 as miliary tuberculosis in man. For this purpose I shall describe the 

 changes that I found in three series of cases of miliary tuberculosis in 

 children, representing, as we shall see, three different stages of develop- 

 ment. In the first series the lungs exhibited all the anatomical appear- 

 ances of acute miliary tuberculosis. On microscopical examination it was 

 found that the nodules were due to groups of alveoli (with the correspond- 

 ing infundibula) being filled with and distended by a fibrinous material 

 that contained granules and a few small cells ; generally these latter oc- 

 cupied the centre of the alveoli. The walls of the alveoli were hardly 

 distinguishable ; and the capillary vessels were not permeable, as shown 

 by the fact that, in well-injected preparations, the injection did not pene- 

 trate into the capillaries of the alveolar septa. The alveoli next to these 

 nodules contained the same fibrinous material ; but they were not filled up 

 by it completely ; and their epithelium could be distinctly recognized, 

 having become wholly or partially detached, the individual cells being 

 somewhat enlarged, and some of them containing two nuclei. Here the 

 injection material penetrated the capillary blood-vessels more or less 

 perfectly: the alveoli of the neighbouring parts contained either a 

 small amount of fibrinous material, besides isolated young cells, or a ho- 

 mogeneous gelatinous substance that had become stained with haematoxy- 

 lin. The epithelium was very distinct, its cells granular. In some of 

 the alveoli the epithelial membrane was more or less detached from the 

 alveolar septa ; the capillary blood-vessels were perfectly permeable. 



In the second series of cases of miliary tuberculosis, in which the lungs 

 did not differ in macroscopical appearance from those of the first series, but 

 in which the process had lasted longer, the microscopical appearances were 



