716 INTERNAL SECRETIONS AND PRESERVATION OF LIFE. 



As the "plate" leaves the cell the external portion gradually 

 increases in size and is connected with the rest by a thread. 

 Several of these may leave the cell together from different parts 

 of the periphery. He also found them to stain with methylene- 

 blue and h&matoxylin. It is evident that we have in the red 

 corpuscle a diminutive nucleated sponge capable of absorbing 

 haemoglobin from the serum of the pulmonary alveoli and of 

 dealing it out in the blood-stream as needed by the plasma. 

 This feature and the functions of the leucocytes just 

 described introduce complemental factors in the respiratory 

 process as we interpreted it in the second chapter. It now 

 seems to us that the whole process is summarized in the fol- 

 lowing conclusions: 



1. The true respiratory areas in the pulmonary lobules are 

 composed of the alveolar endothelial plates (the non-nucleated epi- 

 thelium) and groups of eosinophile leucocytes (the nucleated epithe- 

 lium) interposed between the former. 



2. The eosinophile cells are the bodies in which hcemoglobin 

 is formed from the proteids, bilirubin, and iron, absorbed by their 

 parent-cells, the neutrophiles, in the intestinal canal. 



8. When the eosinophile leucocytes reach the alveoli from the 

 liver via the heart they assume an orderly arrangement and alter 

 their shape, so as to form the alveolar epithelium. 



4. The eosinophile leucocytes supply the adjacent plasma with 

 their hemoglobin, and the latter is absorbed by the underlying red 

 corpuscles along with the oxygenized secretion (oxidizing sub- 

 stance). 



5. Leucocy to genesis being governed by the adrenal system, the 

 main factors of the above respiratory process, the production of 

 eosinophile cells and of adrenal secretion, are thus dependent upon 

 the functional integrity of this system. 



6. The neutrophile leucocytes which accompany the eosino- 

 philes migrate from the capillaries of the pulmonary artery to the 

 perialveolar lymphatics, and supply the interlobular structures 

 with their nutritional and functional elements: i.e., peptones, 

 myosinogen, and fibrinogen. 



7. During certain diseases neutrophile and basophile leuco- 

 cytes may also penetrate into the alveoli and be found in the 

 sputum. 



