7 6 



GROWTH 



carbohydrate need not necessarily be included in the diet. This 

 question also was investigated experimentally by Osborne and 

 Mendel and they found that the response of the rats was largely 

 determined by the quantity of fat in the diet. One ration (meat 

 residue 20 per cent, beef fat 61 per cent, butter fat 14 per cent, 

 salt mixture 5 per cent, vitamin B tablets in addition) permitted 

 a fairly rapid rate of growth to be maintained. A ration con- 

 taining casein 15 per cent, and fat 80 per cent was, however, 

 decidedly less satisfactory. 



CRO-TH OH DIET3 IB WHICH HEARLY ALL 



OF TEE ENERGY WAS SUPPLIED BY 



PHOTEIH 



Ceeoln 

 Zein & 



Salt alxtore 5 

 Alfalfa 0.4 e-daily 

 Yeaet 0.2 g.dally 



Heat real due 90> 

 Clladln 5 

 Salt Dlxture 5 

 Alfalfa 0.4 g. dally 

 Yeast C.2 g. daily 



Figure 49. Growth on a diet practically free from both fats 

 and carbohydrates. 



In the last series to be described, the ration contained a very 

 high percentage of protein and was practically devoid of both 

 carbohydrate and fat. The ration consisted of meat residue 90 

 per cent, gliadin 5 per cent, salts 5 per cent, together with daily 

 additions of yeast 200 mg., and alfalfa 400 mg. It will be ob- 

 served from the chart that the animals grew rapidly, but the 

 period of rapid growth was shortened, so the adult size was 



