CUTANEOUS RESPIRATION 597 



reach the enormous degree of ninety atmospheres, while 

 that of the surrounding water amounts to only about one- 

 fifth of an atmosphere, it is at once evident that here there 

 can be no possibility of a diffusion process, but that neces- 

 sarily we are dealing with a true oxygen secretion. Moreau 

 showed that if the swim-bladder be emptied by puncture 

 with a trocar it becomes filled again by secretion of a gas 

 consisting mainly of oxygen. Bohr was able to prove that 

 this secretory process is under the regulation of the nervous 

 system, and that on section of the intestinal branches of the 

 vagus nerves it fails. 42 



In conclusion it may be well to briefly touch upon the 

 question of the means at disposal of the economy to com- 

 pensate by the function of other organs for loss of the 

 respiratory work of the lungs. 



Partial Pulmonary Exclusion. Hellin 's experiments in 

 reference to unilateral excision of the lung may be men- 

 tioned first, which have attained a certain degree of actual 

 success, from the prevailing efforts of surgeons to bring 

 the lungs into the field of accessibility to operative proced- 

 ures. Hellin had observed that rabbits, one lung of which 

 he had excised, usually bore the procedure well. The dysp- 

 no3a at first appearing generally disappeared in the course 

 of a few hours ; and, what was even more remarkable, the 

 amount of eliminated carbonic acid, which was obtained from 

 the single lung after the operation, was quite as large as 

 that which was previously excreted from the two lungs 

 together. This was made possible primarily by an increase 

 in the work of the heart, which in consequence soon became 

 hypertrophied. There later developed a distinct dilatation 

 of the blood-vessels of the lung, and in the end there was a 

 distinct hypertrophy of the alveolar pulmonary tissue 

 itself. 43 



"Literature upon Gas Secretion in the Swim-bladder: Ch. Bohr, NagePs 

 Handb. d. Physiol., 1, 163-166, 1905; W. Cronheim, Handb. d. Biochem., 4", 

 431-432, 1910. 



48 D. Hellin (Warsaw), Arch. f. exper. Pathol., 55, 21, 1906. 



