409 



shaped, the smaller ends bounding the lumen. The "Halbmonde- 

 Zellen" mentioned by Frankenhausek could not be found. In the 

 larger bronchi its glands are distinctly larger than in the smaller 

 bronchi, and the gland cells are also a little larger, though of the same 

 type. From a series of measurements taken of bronchi where the 

 glands were found to disappear, it was found that they disappear in 

 bronchi between 0,3 — 0,4 mm in diameter, so that a person is really 

 justified in saying that they extend into the finer ramifications of the 

 bronchi. 



In addition to the cat's lung the lung of man and the lung of a 

 full grown pig were examined with the same points in view. The same 

 points of disapperance with slight variations were found for cartilage, 

 goblet cells, cilia and mucous glands in the lung of man as in the 

 cat, but the results obtained from the study of the lung of the pig 

 varied considerable from those obtained in the study of the lungs of 

 the cat and of man. By referring to the table it will be seen that 

 in the pig cartilage disappeared in bronchi between 0,5 and 0,6 mm in 

 diameter; glands in bronchi 0,6 — 0,7 mm in diameter; goblet cells in 

 bronchi 0,6 mm in diameter and cilia in bronchi about 0,3 mm in diameter. 



In order to show the points of disappearance of cartilage, goblet 

 cells, cilia, and glands found by the authors that have been read, and 

 in order to compare these with the results obtained, the accompanying 

 table has been prepared. It will be npticed in looking over the table 

 that, with two exceptions, the authors have given definite points where 

 they have found them to disappear. The two exceptions are Franken- 

 HAUSER who says goblet cells are still present in middle-sized bronchi 

 and Remak who says glands are found in the finest ramifications of 

 the bronchi. 



Comparing my own results obtained in the study of the lung of 

 man and the cat with those referred to, it will be seen that they do 

 not in most cases vary much. The point of disappearance of the car- 

 tilage agrees with all, except that given by Frankenhauser, who found 

 it to disappear in bronchi 0,4 mm in diameter, and Kölliker who found 

 it to disappear in bronchi 0,85 mm in diameter. The point determined 

 upon was in bronchi 0,94 mm in diameter. 



With respect to goblet cells, the agreement is not so uniform. 

 The results agree only with that. of Kölliker, who says goblet cells 

 disappear in bronchi between 0,5 — 0,4 mm in diameter. Frankenhauser 

 as already stated, gives no definite point, but says they are still pre- 

 sent in middle-sized bronchi. Schulze says they disappear at the 

 point of transition into the alveolar passages. 



