598 GAS INTERCHANGE IN LUNGS 



Cutaneous Respiration. While in amphibia, as is well 

 known, cutaneous respiration 44 plays an important function 

 and may in fact replace the pulmonary respiration, this is 

 altogether subsidiary when we come to deal with the keratin- 

 ized epidenn of warm-blooded animals. According to the 

 coinciding investigations of Kegnault and Beiset, Ziilzer, 

 Bohr and others, the skin at best cooperates to the extent 

 of one per cent, of the total gas exchange. This has been 

 confirmed, too, by recent studies in Zuntz's Institute, 45 in 

 which the arm of the experiment subject was surrounded 

 by a gas mixture containing about ninety per cent, of oxygen 

 in a closed glass sleeve, and the oxygen consumption de- 

 termined. The results showed again (extending the calcu- 

 lation to the entire body surface) that the intake of oxygen 

 by the skin does not exceed about one per cent, of that by 

 the lungs. The severe lesions, perhaps fatal, which are met 

 in animals in which the most of the skin has been varnished, 

 are certainly therefore not due to a fault of the cutaneous 

 respiration. (Usually these are regarded as connected with 

 the marked chilling of the animals ; yet there are cases in 

 which this explanation is insufficient. The latter have led 

 Babak and other authors to revive the old supposition of 

 an accumulation of some unknown poisonous material within 

 the body; but nothing positive is known about it.) 



Oxygen is absorbed much better by the serous mem- 

 branes than by the skin. Thus 0. Pascucci has proved by 

 certain admirable experiments that guinea-pigs are able to 

 remain alive in an atmosphere of nitrogen, if oxygen be 

 furnished to them intraperitoneally. 46 



Intestinal Respiration. An exchange of gases may also 

 take place in the intestinal wall between the intestinal con- 



44 Literature upon Cutaneous Respiration: Ch. Bohr, NagePs Handb. d. 

 Physiol., 1, 160-163, 217-218, 1905; A. Lowy, Handb. d. Biochem., 4', 167-171, 

 1908. 



46 G. Franchini and L. Preti (Lab. of N. Zuntz), Biochem. Zeitschr., 9, 

 442, 1908. 



"O. Pascucci (Luciani's Lab., Rome), Arch, per le Scienze med., 35, 347, 

 1909. 



