246 BOTANICAL GAZETTE [NOVEMBER 
grain was treated to each concentration ten minutes, allowed to 
drain, stand moist for two hours, and then thoroughly air dried 
before an electric fan. The grain was then thoroughly ground in 
a mill, and extracts of 8 gm. lots made in 100 cc. of redistilled water. 
Ascending quantities of the water extract were then added to test- 
tubes each containing 5 cc. of soluble starch prepared as for the 
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STARCH DIGESTION 
Fic. 9.—Effect of formaldehyde treatment on diastatic activity of wheat extract, 
seeds treated 10 minutes; concentration of formaldehyde used in treatment varied, 
and also cubic centimeters of seed extract used: height of lines indicates amount of 
starch remaining undigested after incubation one hour at 40°C.; 5 cc. 25 per cent » 
soluble starch solution used in each test (all conditions shown in duplicate). 
other tests. After incubation for one hour at 40°C. complete 
digestion had occurred in the controls containing 5, 10, 15, and 20 CC. 
respectively of the extract of untreated seed. Fig. 9 shows that 
despite a few unexplained irregularities, the general trend is obvi- 
ously a reduction in the amount of starch digestion, with a rise in 
the concentration of the formaldehyde originally used in treatment 
of the seed. This holds for 5, 10, 15, and 20 cc. seed extract tests 
