104 GROWTH 



the period of youth is lengthened and that the length of the 

 period we denote maturity is unaffected? At first thought this 

 seems highly improbable, but some data published by Osborne 

 and Mendel are suggestive. They state 55 that of the stock ani- 

 mals they observed, less than one-third lived to be two years 

 old. Yet, of a group of stunted females they had under observa- 

 tion, all lived beyond that age, and all bore young at a time 

 when they would probably have been dead of old age if they 

 had been normally fed. It may be that the surest way of attain- 

 ing long life is slowly to starve to death. 



We have just discussed the data of a group of reports that 

 would seem to minimize any untoward effects of undernutri- 

 tion. In fact, Osborne and Mendel would seem to take the posi- 

 tion that within reasonable limits the power to grow is never 

 suppressed. One might infer from their statements that the 

 failures to attain normal size were due to accidental causes, such 

 as would be the more likely to attack animals in a "weakened" 

 condition. There is, however, another group which seems dis- 

 tinctly to take a somewhat opposing view, that severe under- 

 feeding in youth will be followed by unfavorable, and perma- 

 nent, effects. Among the more important of these may be 

 mentioned Aron. 49 In one experimental series he described two 

 puppies, A and B, which were placed under observation at an 

 age of three months. B was fed generously , A was given only a 

 sufficient quantity to keep his weight constant. He became ex- 

 tremely thin, but increased in length and height until about the 

 200th day, when apparently no further change occurred. The 

 author stressed the point, however, that he remained extremely 

 active. Dog A was continued on this limited diet for about a 

 year altogether, and at that age dogs have normally ceased 

 growth. At that time he was measured, and his ration was 

 gradually increased until he was given a decidedly generous ra- 

 tion. On the 500th day he was again measured, and the meas- 

 urements were practically identical with those taken 150 days 

 earlier, when he was in a state of emaciation. The weight at the 



