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a. 



Reprinted from THE AMERICAN JOURNAL OF PHTSIOLOQT 

 Vol. 69, No. 1, February, 1922 



-OGlf 



LIBRARY 

 G 



STUDIES IN THE REGENERATION OF BLOOD 1 



ZALIA JENCKS 



From the Sheffield Laboratory of Physiological Chemistry, Yale University, 



New Haven, Connecticut 



Received for publication September 8, 1921 



Studies in the regeneration of blood after simple anemia have been 

 made on many species of animals and on man. Although various phases 

 of the growth of blood have been extensively investigated in connection 

 with destruction of the erythrocytes by chemical agents or specific 

 diseases, much less information is available regarding recovery from 

 the anemias produced by hemorrhage. 



Many, if not most, of the earlier researches lack a convincing char- 

 acter because relatively few of the variables have been sufficiently 

 taken into account. Heretofore the work on blood regeneration has 

 been on animals whose dietary control was not complete. Inasmuch 

 as the more recent investigations of nutrition, conducted on laboratory 

 animals, have made it possible to control a variety of dietary factors, 

 only one variable will need to be taken into consideration for the dura- 

 tion of a particular series of experiments. 



The present studies on albino rats were undertaken because of the 

 relatively large amount of information available concerning the dietary 

 requirements of these animals. The rat is small enough to make 

 possible the use of large numbers for. experimental purposes and it has 

 been employed as a laboratory animal for so many generations that 

 laboratory conditions do not make its confinement unnatural. Our 

 rats were from the colony of the Connecticut Agricultural Experiment 

 Station. They were kept on a standard synthetic diet 2 while in experi- 



1 Material for this paper was taken from the dissertation submitted for the 

 degree of Doctor of Philosophy, Yale University, 1921. 



3 Standard diet used : per <**t 



Cornstarch 50.5 



Casein 18.0 



Lard 18.0 



Washed butter 9.0 



Salt mixture 4.5 



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