ANOXYBIOTIC PROCESSES 577 



active in well fed animals than in fasting subjects from 

 the studies of Barcroft and Shore. 49 In the kidney the in- 

 terchange of gases is undoubtedly increased in the course 

 of an experimentally induced diuresis (as indicated by 

 investigations of Barcroft, Brodie, Cullis and Hamill). One 

 may strikingly maintain, according to Vernon, the gas in- 

 terchange at a fairly constant level for many hours by per- 

 fusing a fresh mammalian kidney with Locke's solution to 

 which have been added a little blood-serum and urea. 50 



Gas Exchange of the Intestine. Finally it should be 

 added that the gas exchange of the intestine has been in- 

 vestigated by v. Frey, Cohnheim and by Brodie 51 (in asso- 

 ciation with Halliburton, Vogt and Cullis), and that the 

 results would indicate that whenever there is an increase 

 of absorption (whether induced by contact of water, dilute 

 salt solutions, peptone or dilute acids) a rise in the gas 

 exchange ensues. 



The examples cited are sufficient to show the lines along 

 which these studies tend. The most important general re- 

 sult that stands out is the fact that practically always 

 increased functional performance by an organ is accom- 

 panied by an increase in its gas interchange. 



Anoxybiotic Processes. These considerations of tissue 

 respiration may be concluded with a short reference to 

 anoxybiotic processes. 



Bunge in 1883 called attention to the remarkable fact 

 that there are animals which are capable of living in the 

 absence of oxygen. These are the intestinal worms, para- 

 sitic in the warm-blooded animals, forms of life whose needs 

 for heat-production are necessarily reduced to a minimum, 

 as they normally inhabit a living incubator. Mud-dwelling 

 forms live under comparable respiratory conditions to those 



49 J. Barcroft and L. E. Shore (Physiol. Lab., Cambridge), Jour, of 

 Physiol., 45, 296, 1912. 



M H. M. Vernon (Oxford), Jour, of Physio!., 35, 53, 1906; 36, 81, 1907-08. 



51 Brodie, in collaboration with W. C. Cullis, W. D. Halliburton and H. 

 Vogt, Centralbl. f. Physiol., 23, 324, 1909; Jour, of Physiol., 40, 136, 173, 1910. 

 37 



