THE SWEET POTATO. 41 



As far as this experiiiieiit goes, it seems that tlie 

 given variations in fertiHzer produced a ditt'erenee 

 in starch percentage, although not nearly as great 

 as a selection of varieties fertilized in the same way. 

 If this sliould be confirmed and applied to a variety 

 naturally rich in starcli, that would, of course, be a 

 farther means of evolving a first-class starch-yield- 

 ing variety. 



It is not at all improbable that the method of culti- 

 vation and the soil in which the sweet potato grows 

 maj' seriously influence the starcli percentage, but, 

 as far as known to the writer, no experiments have 

 been made to determine that. 



That storing makes the sweet potato sweeter is 

 well known. By a series of analyses instituted by 

 the South Carolina and Texas stations, independ- 

 entlj', it has been determined that an actual increase 

 of sugar, mainly cane sugar, takes place during stor- 

 ing, and that this is accompanied by a decrease in 

 starch. It is strongly suggested by Mr. Shiver that 

 the starch which is lost is actually changed into cane 

 sugar. The general trend of the table seems to 

 favor this view. Still, there are in the analyses 

 quoted in Bulletin 63 some instances which are so 

 much out of accord with the averages given that they 

 strongly suggest that the samples may have been 

 much less uniform than was supposed. For exam- 

 ple: In Table XVIII we find the two samples of 

 Bunch Yam, from different sources, analyzed on 

 November 28, 1898, as follows : 



Water. Starch. Glucose. Sucrose. 



Per cent. I'er cent. Per cent. Per cent. 



Bunch Yam (No. 1) 72.37 15.12 1.09 4.45 



Bunch Yam (No. 2) 67.99 19.58 .56 4.49 



