204 Pecan-Growing 



of pecans distributed in such a way as to give the nut a high 

 nutritive value as a source of protein. Cajori ^ discovered 

 the principal protein of the pecan to be a globulin, and 

 reports the distribution of the nitrogen in the pecan globulin 

 as follows: 



Per cent 

 Amide nitrogen 9.8 



Humin nitrogen 3.6 



Argine nitrogen 22 . 9 



Histidine nitrogen 3.7 



Cystine nitrogen . S 



Lysine nitrogen 6.2 



Monoamino nitrogen 51 . 7 



Non-amino nitrogen 0.8 



Following Friedeman's analyses showing that the integu- 

 ment or outside cuticle of the pecan kernel contains a con- 

 siderable percentage of tannins, Cajori^ conducted feed- 

 ing experiments with rats and secured much more rapid 

 growth when the rats ate pecan kernels from which the cuticle 

 had been removed, thus furnishing evidence that the tanning 

 of the cuticle or integument was a hindrance to the best 

 growth of the rats. The protein of the pecan, however, is 

 of a very choice character. Some of the earlier investigators 

 referred to the protein of nuts as vegetable casein because it 

 closely resembled the protein of milk. The amino acids, lysine, 

 and cystine, which have been found to be essential to growth, 

 are present in relatively large quantities in the pecan. 

 Especially is this true for lysine, as shown by the foregoing 

 tabulation. 



PECAN om, 



The fats of pecans, which are their leading food principle, 



^ Journ. Biol. Chem. Vol. 49, No. 2, 1921. 



^ Journ. Amer. Cbem. Soe. Vol. 42, No. 11, 1920. 



