224 



Bulletin 230. 



These tubers were rendered mealy by cooking and were of good 

 flavor and color. As was to be expected, those baked lost some 

 moisture, but the loss was not great. Those boiled lost moisture in 

 each case except one, when the gain was slight. It should be stated, 

 however, that in another boiled sample of Wonderful, not recorded 

 here, there was a gain of 9.63 per cent. 



These figures and observations seem to point to the conclusion 

 that although the starch grains expand greatly on boiling, yet the 

 volume of potato substance is not materially increased because in 

 expanding, the starch grains incorporate the water which was origi- 

 nally in the tuber in a free state. In other words, the mass acts some- 



FiG. 178. — Tuber growing in a sloping -position. The stick above the level of the soil. 



what as a sponge. If the cortical layer is thin, the skin netted, 

 and the external medullary area uniform, the texture crisp and the 

 internal medullary area small, the tuber generally becomes mealy 

 when boiled. 



Account of Experiments. 



The characteristics of quality which have been mentioned may 



vary slightly in different varieties of potatoes. For these studies 



Doe's Pride was used. This is a late variety, and in general, one 



producing a good yield. It is oblong-oval in shape, with long, 



medium to shallow eyes. The skin has a slightly pinkish tinge 



