Dec, 1921] PATON — POLLEN AND POLLEN ENZYMES 497 







1st Weight (mg.) 2d Weight (mg.) Gain (mg.) 



(c) 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) . 809 815 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 with Fehling'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 199H50) 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 



1. 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 1 : 100 and 

 1 : 10,000. 1 cc. of this dilution was then placed in sterile petii dishes and 

 agar plates were poured. The plates were then incubated at 37 lor 24 

 hours, in an inverted position to prevent moisture from washing off cultures, 



