496 AMERICAN JOURNAL OF BOTANY [Vol. 8, 



It was found that the pistils with the active pollen had noticeably softened 

 and the styles could easily be teased apart with dissecting needles, while 

 the pistils with boiled pollen were still firm. The longitudinal and cross 

 sections of the pistil treated similarly showed the same results. Inciden- 

 tally, the chemotropism of the pollen grain for the stigma was conspicuous 

 in the active pollen tubes. 



2. Equal amounts of desiccator-dried ground Easter lily pistil were 

 treated with poller, and tested quantitatively for sugar as in the invertase 

 test already described. 



Dried Ground Pistil Boiled Pollen Water Toluol 



(a) 150 mg 100 mg. in 5 cc. water 10 cc. 4 cc. 



100 mg. ungerminated 15 cc. 



• " 100 mg. germinated 



" 100 mg. ground 



(b) Solution 15 drops, alkaline to neutral. 

 Fehling's solution 15 drops. 



Boil in water bath Y% hour. 



Filter on weighed, desiccator-dried paper. 



Dry in oven and desiccator. 



Weigh again. 



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



(c) Boiled pollen 711 716.3 5.3 



Ungerminated 711. 2 720.15 8.95 



Germinated 720.28 729.00 8.72 



Ground 827.00 839.00 12.00 



3. The action of pollen on pectin was tested. The pectin used for the 

 tests was piepared from the white inner skin of grape fruit, as follows: 



Remove the white and boil in water. 



Put through a meat chopper. 



Leave in cold water 24 hours. 



Boil from V 2 to 1 hour. 



Strain through cheesecloth. 



Filter. 



Concentrate by heating over a water bath. 



Add 95 percent alcohol to precipitate. 



Filter. 



Wash with absolute alcohol. 



Dry in a desiccator. 



For the tests the following amounts were used : 



(a) 3 cc. of pectin solution (300 mg. in 20 cc. of water), 300 mg. of pollen, 15 cc. of water, 



8 drops of toluol. 



(b) 15 drops of the pollen-pectin solution, 15 drops of Fehling's solution, or Benedict's 



solution. Treat as stated above (2 b). 



