486 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8, 
suspensions was taken. To each portion 15 cc. of fresh Fehling's solution 
was added. The tubes were placed in a water bath and boiled an hour. 
The solutions were then filtered on desiccator-dried, weighed filter paper, 
and the copper precipitate was washed with hot water until free from the 
excess of Fehling's solution. The filter papers were then dried first in an 
oven and then in a desiccator and again weighed. The gain in weight 
represents the amount of reducing sugar present. 
The weights of the papers are shown in table 8. 
Table 8 
1st Weight 
2d Weight 
Gain 
Ungroiind pollen 
824 mg. 
857.05 mg. 
33-05 mg. 
832 mg. 
860.2 mg. 
28.2 mg. 
831-5 nig. 
857 mg. 
25-5 mg. 
843 mg. 
845-35 mg. 
2.35 mg. 
Sugar solution only 
828 mg. 
829.1 mg. 
I.I mg. 
The gain in the unground pollen, which appears larger, is relatively 
less because in this test the 300 mg. was all pollen, while the 300 mg. in 
the other tests was partly powdered glass. From these figures and from 
several similar tests it seemed evident that in the case of Easter lily pollen 
invertase, at least, there was no advantage in previously germinating the 
pollen grains. Repetition of this type of experiment might show a wide 
range of variation both for kinds of pollen and for their enzymes. 
The data obtained in testing for pectinase in Easter lily pollen confirmed 
the opinion that for this kind of pollen there was no gain in pectinase as a 
result of germination. ^ 
Tests for Amylase 
The method used was to test a known quantity of starch paste with 
active pollen and an equal quantity with boiled pollen for a control. First, 
10 cc. of I percent starch paste was used with 150 mg. of pollen. Later, 
5 drops of I percent starch in 10 cc. of water was found to be a better dilu- 
tion. Toluol was used as an antiseptic. The tubes were allowed to stand 
in a warm room for 24 hours and were shaken occasionally. Two portions 
of 15 drops each were then taken from each tube, and to one was added 2 
drops of iodine to see if the starch had disappeared, and the other was 
heated with 15 drops of Fehling's solution to see if sugar had appeared. 
The results are seen in table 9. 
In these tests, as in those already mentioned, the ground pollen was 
more active than the unground, but the germinated pollen did not appear 
to be more active than the ungerminated. 
From table 10 it is seen that all kinds of pollen tested contained an 
amylase, but that this amylase was less active in the apple pollen (Siberian 
crab) and in that of the magnolia (cucumber tree) than in the other kinds. 
