3^2 



Scientific Proceedings (123). 



± .078. It must also mean the simultaneous laying down of more 

 protein and carbohydrate, for the following reasons: (1) the 

 amount of ether extract found in tubers is insufficient to account 

 for all the increase in dry matter; (2) the protein and carbohydrate 

 are sufficient to account for it; (3) the protein and carbohydrate 

 are not correlated with the dry matter, but are correlated with 

 each other negatively. As these organic constituents are in- 

 creased the minerals are decreased, as is evidenced by the coeffi- 

 cient of —.380 db .076 between the ash and dry matter. In fact 

 the ash bears a negative relation to all the other factors studied, 

 although in the majority of cases the coefficient is too small to be 

 of significance. 



From the above data we can conclude that it should be en- 

 tirely possible to improve the potato tuber as regards protein, 

 provided the dry matter be increased. Mealiness can then still 

 be maintained. This improved tuber will probably be spheroidal, 

 instead of long in shape, since the longitudinal diameter is cor- 

 related positively with the starch content. 1 



Table I. Summary of Correlations Among the 

 Various Factors in Potato Tubers. 





Dry 

 Matter. 



Nitrogen. 



Ash. 



Ether 

 Extract. 



Starch plus 

 Sugar. 



Specific gravity 

 Dry matter. . . . 



Ash 



Ether extract. . 



+.637 ±.054 



-.233 ±.084 

 +.034 ±.090 



—.311 ±.082 

 -.380 ±.076 

 —.052 ±.090 



— .i64±.o87 

 +■333 ±.078 

 +.2i6±.o86 

 -.u6±.o88 



+.2i8±.o86 

 +.059 ±.090 

 -•590±.058 

 -.223 ±.085 

 +.004 ±.090 



176 (1923) 



Yeast as a source of vitamine-B for the growth of rats. 



By CORNELIA KENNEDY and LEROY S. PALMER. 



[From the Section of Animal Nutrition, Division of Agricultural 

 Biochemistry, University of Minnesota, St. Paul, Minn.] 



Yeast is commonly considered the richest source of vitamine- 

 B for the growth of young animals. We have fed groups of rats 



1 Renski, M. D., Abs. in Exp. Sta. Rec. 191 1, xxiv, 439. 



