56 



Messrs. Dreyer, Ray, and Walker. 



[Sept. 30, 



4. Dreyer, G., Eay, W., and Walker, E. W. Ainley, 1912, "The Size of the Aorta in 



certain Animals and its Relation to their Body Weight," 'Journ. Physiol.,' 

 vol. 44, p. viii. 



5. Meeh, K., 1879, " Oberflachenmessungen des menschlichen Korpers," ' Zeitschr. f. 



Biologie,' vol. 15, p. 425. 



6. Keilson, Hermann, 1898, 'Beitrag zur Lehre von der Pulsfrequenz,' Dissei't. 



Konigsberg in Pr. 



7. Thoma, P., 1882, ' Untersuchungen iiber die Grosse und das Gewicht der anato- 



mischen Bestandtheile des menschlichen Korpers in gesunden und kranken 

 Zustand,' Leipzig. 



The Size of the Trachea in Warm-Blooded Animals, and its 

 Relationship to the Weight, the Surface Area, the Blood 

 Volume, and the Size of the Aorta. 

 By Georges Dreyer, William Ray, and E. W. Ainley Walker. 



(Communicated by Francis Gotch, F.R.S. Received September 30,- — ■ 

 Read December 5, 1912.) 



(From the Department of Pathology, University of Oxford.) 



The analysis of data collected in connection with the investigation of a 

 number of problems in immunity has led to a series of results, in part 

 already published, bearing upon the blood and circulation. The conclusion 

 was reached that in certain cases a precise and definite relationship to the 

 body surface exists in warm-blooded animals in accordance with the formula 

 ~W n /a — k, where W is the body weight of the animal, a represents the mass of 

 the body fluid, tissue, or organ under investigation, h is a constant, and the 

 value of n is approximately O70-O72. 



In view of the fact that the carriage of oxygen is one of the chief 

 functions of the circulation, and that the volume of the blood (1), (2), and 

 the aortic area (3), (4), (area of cross-section of aorta), have been shown by 

 us to be proportional to the body surface in warm-blooded animals, while, as 

 we have also found, the total oxygen capacity is the main factor in deter- 

 mining the size of the heart (5), it appeared to be of interest to examine the 

 size of the channel by which the oxygen gains access to the lungs. 



Accordingly, the trachea was measured in two species of mammal and one 

 bird, namely, guinea-pig, rabbit, and ptarmigan. The animals used were 

 healthy individuals in good condition, not previously experimented upon, 



