Dec, I92I] PATON — POLLEN AND POLLEN ENZYMES 497 
1st Weight (mg.) 
2d Weight (mg.) 
Gain (mg.) 
Austrian pine (active) 
767.5 
789 
21.5 
" (boiled) 
779 
785 
6 
Norway maple (active) , 
778 
797 
19 
" (boiled) 
782 
794 
12 
Magnolia (active) 
814 
835 
21 
(boiled) 
8oq 
815 
6 
Apple (active) 
795 
805 
10 
" (boiled) 
799 
807 
8 
(d) In this test 150 mg. of pectin and 150 mg. of ground pollen and glass were used, and the 
entire amount precipitated v/ith FehHng's solution. 
1st Weight 2d Weight Gain Actual Gain 
(mg.) (mg.) (mg.) (mg.) 
Apple pollen (active) 765 963 i98(-i5o) 48 28 
" (boiled) 754 924 i7o(-i5o) 20 
Red maple (active) 767 969 202(-i5o) 72 23 
" (boiled) 748 947 I99(-I50) 49 
(e) Later similar tests were made with seven other kinds of pollen, daisy, dock, goldenrod, 
white pine, ragweed, rye, and timothy. All gave positive results for the pectinase 
test. 
Subtracting the constant 150 mg. of pollen and glass, the actual gain of 
sugar from pectin for the apple pollen, as compared with the control, is 
28 mg. and for the red maple pollen 23 mg. This is larger than in the 
previous table, but larger quantities were used. Not only do the quanti- 
tative determinations show that pectin is converted into sugar by active 
pollen, but also in comparing the tests and their controls in the test tube 
it was very noticeable that the reduction of Fehling's solution was greater 
with unboiled pollen. 
4. Another test which confirmed the presence of a pectinase was made 
for me by Mr. F. B. H. Brown, Yale University. Mr. Brown in his work 
on tropical woods, by a special method of technique, has succeeded in making 
sections one eighth as thick as are usually cut. When sections of dragon- 
tree wood (Dracaena aurea), Tecoma obtusa, and a species of roselle were 
floated on water with Easter lily pollen and allowed to remain from 24 to 48 
hours, on examination with the microscope it could be plainly seen that in 
many places the middle lamellae of the cells had been completely digested. 
Permanent slides were prepared. 
Tests for Bacteria and Molds on Pollen 
I. One method was as follows: Extracts of nine different pollens were 
made, 50 mg. in 10 cc. of water. This extract was then diluted by the 
usual milk- testing method in sterile bottles to dilutions of i : 100 and 
I : 10,000. I cc. of this dilution was then placed in sterile petii dishes and 
agar plates were poured. The plates were then incubated at 37° for 24 
hours, in an inverted position to prevent moisture from washing off cultures, 
