292 Biology in America 



have recorded in such detail, are in perfect harmony with the 

 conclusions arrived at by our experiments and observations 

 with man, and serve to strengthen the opinion, so many times 

 expressed, that the dietary habits of mankind and the dietary 

 standards based thereon are not always in accord with the 

 true physiological requirements of the body. ' ' 



There is one experiment in the foregoing series regarding 

 which a further word may be said. In this experiment a 

 dog which had been fed on a diet of meat, milk, bread and 

 lard was changed to a diet of bread and lard only, the food 

 and fuel value however of the diet remaining unchanged. 

 "In four days' time however a change began to creep over 

 the animal ; the appetite diminished, and there was apparent 

 a condition of lassitude and general weakness which deterred 

 the animal from moving about as usual. 



"During the next week the animal grew steadily worse, 

 and would eat only when coaxed with a little milk or with 

 bread softened with milk, the diet of bread and lard being 

 invariably refused. There was marked disturbance of the 

 gastro-intestinal tract; bloody discharges were frequent; the 

 mucous membrane of the mouth was greatly inflamed and 

 very sore ; body-weight fell off, and the animal was in a very 

 enfeebled condition. This continued until December 4, with 

 every indication that the animal would not long survive, but 

 by feeding carefully with a little milk and occasionally some 

 meat, improvement finally manifested itself, and by December 

 18 there was good appetite, provided bread was not con- 

 spicuous in the food. Body-weight . . . was . . . slowly re- 

 gained (until finally) ... in general condition there .was 

 nothing to be desired." 2 



Similar results have been obtained by Hopkins and Nevill 

 who kept twenty-four young rats on a diet of protein, starch, 

 lactose (milk-sugar) and salts. They ate well and took 

 sufficient food to supply them with needed energy, but soon 

 ceased to grow and in a few days actually began to lose 

 weight, fourteen of them dying in forty days. With six of 

 the rats there was added to the diet, after the decline in weight 

 had commenced, a small portion of milk daily, which was 

 followed by an immediate improvement in health, and re- 

 newed growth. 



There are certain problematical diseases in man, which' 

 may be due to a lack of something in the food. Beri beri, a 

 disease common among Filipinos, Japanese and East Indians, 

 and characterized by paralysis, swelling and degeneration of 

 the muscles, has been attributed to an extensive diet of 



2 The foregoing quotations arc from Ohittenden, "The Nutrition of 

 Man," pp. 187 et seq., by permission of Fred'd A. Stokes Co. 



