SCIENTIFIC PROCEEDINGS 



Abstracts of Communications. 



One hundred thirteenth meeting. 



College of the City of New York, New York City, February 16, 

 i Q2i, President Calkins in the chair. 



62 (1644) 



The reserve energy of actively growing embryonic tissues. 



By MONTROSE T. BURROWS. 



[From the Department of Surgery, Washington University Medical 

 School, and the Research Laboratory, Barnard Free Skin and 

 Cancer Hospital.] 



In 1902 Fletcher 1 showed that the sartorius muscle of a frog 

 will give a maximum contraction when stimulated every five 

 minutes over a period of two hours in an atmosphere of pure 

 nitrogen. In an atmosphere of oxygen, the same muscle will 

 contract for a much longer time and the fatigue developing in an 

 atmosphere of nitrogen may be removed by placing the muscle 

 again in an atmosphere of oxygen. 



If differentiated muscle has sufficient reserve energy to allow 

 it to contract for a period without oxygen, the question arises, will 

 not the same reserve be found in an actively growing tissue. 



In a previous article in 191 y 2 the author described a method 

 which allows one to study quantitatively the effect of various 

 concentrations of oxygen on the growth of cells in vitro. In that 

 paper the main point studied was the relative effect of pure 

 oxygen and various dilutions of oxygen in nitrogen on the rate 

 and extent of the growth. The tissues used were fragments of 

 heart muscle and other tissue of chick-embryo of various ages. 

 These experiments showed that the growth was practically the 



1 J. of Phys., 1902, xxviii, 474. 



2 Am. Jour, of Phys., 191 7, xliii, 13. 



*33 



