114 C. M. JACKSON AND C. A. STEWART 



been almost completely suppressed for long periods by various 

 inadequate protein diets. It is quite possible that such diets 

 fed in abundant amounts may have less injurious effects upon 

 subsequent growth capacity than does the feeding of restricted 

 amounts of a balanced ration. Mendel ('14) has especially em- 

 phasized the difference between their experiments, in which the 

 diet was ample in calories, and those of simple underfeeding with 

 restricted amounts of a balanced diet. The relation of inanition 

 to other factors producing abnormalities of growth is discussed 

 by Mendel ('17). 



It is also possible, however, that the very surprising results 

 of Osborne and Mendel may be in part explained in another 

 way. It is known that individual rats (and perhaps individual 

 strains) may vary greatly in their resistance to inanition and in 

 capacity for recuperation. In the experiments of Osborne and 

 Mendel, it appears that some individuals are able to maintain 

 their capacity for growth under conditions which would probably 

 in most cases produce a permanent stunting or dwarfing of the 

 body. To what extent this may be true in their experiments is 

 uncertain, since they do not state the total number of animals 

 under experiment, from which the successful cases were selected. 



In our experience, as above stated, a large percentage of the 

 animals die during the course of the severe underfeeding experi- 

 ments, either directly from inanition or indirectly through low- 

 ered resistance to disease. Practically all of the survivors appear 

 permanently stunted in their ultimate capacity for growth, al- 

 though many of them upon autopsy reveal no evident disease. 

 Accordingly, there seems no escape from the conclusion that 

 while a considerable degree of inanition during growth may 

 be followed by prompt and complete recovery upon ample 

 refeeding, more severe and prolonged underfeeding, especially in 

 the very young, reduces materially their capacity for subsequent 

 growth and usually results in permanently dwarfed individuals. 



