782 H. E. KNow.tTon 
TABLE 28. ResprraTion oF FresH Corn POLLEN AT A TEMPERATURE OF 25° C. 
Carbon 
Time Weight dioxide 
of pollen per gram 
per hour 
Hours Grams Milligrams 
DUNE TPA i Is en shee eas ete Re Raed Da tas A ret Pass ote MELD Lo DY ee lg 6 2.11 
SAC) steno ston valet tes WAT Gr egtimie eeerO ues fey ces Sagar eM alae ty ee te eae 6 egvl 
SUN (Dente ark i caeteat ob MAP eu are et Aes Brie ee at glenunal rb, cae ger 6 0.36 
all the stored carbohydrate within the several days that corn pollen 
normally retains its vitality. 
Starch content of pollen 
Microchemical tests show corn pollen to consist almost entirely of starch. 
In dead pollen, there is no apparent diminution in the starch content. 
Actual chemical analysis, using Sachsse’s method, gave the results shown in 
table 29: 
TABLE 29. CarBoHYDRATE ANALYSIS OF Corn POLLEN 
Fresh substance 
Age 
Starch Reducing 
sugar 
Per cent Per cent 
PESTS INE ates reece sea cage acettyatar aeeeete set lovin tga scale HG A Trea 15.2 0.23 
ARG ely Set reet eres a rte ARE Gt Thos laren © yao dae Gs val eee 13.6 0.46 
It is evident, therefore, that the stored food is not exhausted before 
death occurs. 
Amylase activity 
Since starch is the chief reserve carbohydrate, amylase must be an 
important enzyme. Determinations of amylase activity, with both 
fresh and dead pollen, were made by the following method. A weighed 
quantity of pollen (0.1 gram) was ground in a mortar with a few drops 
of distilled water until maceration was complete, after which it was filtered, 
and 2 cubic centimeters of the extract was added to 10 cubic centimeters 
