HEREDITY AND BNVIB0NM1NT. 143 



organic and hereditary tendencies: "Ne devient pas obese qui 

 "Aussi la guerison accident elle ou therapeutique dune obeV 

 n'indique-t-elle pas la disparition definitive dee tendanoei 



ou congenitale." 

 Gulick (1922) has lately undertaken experiments to throw light on 



the question why some persons fatten easily and BOme with difficult 

 He had noted that he himself belongs to n con-fattening strain and 

 that his inclination toward a very copious diet of predominantly 

 starchy nature did not lead him to put on weight, even though Ins 

 round of activity was moderate. So he undertook biochemical, nutri- 

 tional studies on himself. His observation covered nearly 21 mont 

 During part of this time his caloric intake was low, 1,875 '<< -' 7S0; 

 during another part high, 3,400 to 4,100. He found that he fattened 

 somewhat during the period of heaviest feeding. There was. how- 

 ever, always an excess of intake over predictable need, and this 

 increased absolutely and probably even relatively as the intake 

 increased. The fecal nitrogen was 2 1 / 1 > to 3^ times greater during 

 over-feeding than under-feeding. The basal metabolism dun 

 maximum feeding was normal. Gulick concludes that a person 

 longing to the difficultly fattening type shows a wasteful rate of oxida- 

 tion, whether under or over fed, but especially at the latter time. "It 

 seems clear," concludes Gulick, "that throughout the entire experi- 

 mental series there was some factor at work which caused fuel food 

 to be burned more freely than in the average individual. This factor 

 was not an over-active thyroid, as attested by the entirely normal 

 basal metabolism." Gulick concludes that it was "some factor in the 

 chemistry of nutrition" which caused extravagance. This he thinks 

 may very possibly be comparable to the "secondary effect" ol protein 

 enrichment, which, according to Rubner, can raise the specific 

 dynamic action of the food without raising the basal rate. It 

 possible, he says, that the spare type may be accounted for by any 

 factor that produces a high "cost of digestion," just as the i 

 be supposed to suffer from an abnormally low "cost iA digestion" I von 

 Noorden). 



Whatever the fundamental cause may be, the fact remains that in 

 certain families there is a widespread inclination to the production ^i 

 slender individuals, while in other fraternities certain proporti 

 (though usually not all) of any fraternity are fleshy or even 

 Perhaps, as in the case of the Jersey as contrasted with the I 

 the two kinds of individuals do not metabolise their food in the same 

 way; some are spare and muscular, others lay on fat. In any case Wt 

 can not disregard the constitutional factors in build. 



Looking at the matter broadly, we can see that no other tic 

 than that constitutional differences as well a- nutritional differei 



