New York Agricultural Experiment Station. 375 



The cultures. — Hanging drop cultures were made in Van Tieg- 

 hem cells 10 to 12 mm. inside diameter and about 10 mm. high 

 sealed with a mixture of wax and vaseline. The pollen was 

 placed on a clean cover glass, a drop of the culture liquid was 

 applied and some of the same was put into the bottom of the 

 cell so that the liquid in the cell would be of the same composi- 

 tion ae that in the drop. The cover glass was then put into its 

 place and sealed. 



POLLEN CULTURES IN MIXTURE A. 



A spray mixture which for convenience of reference is here 

 called "A" was made from the ordinary commercial materials. 

 It consisted of Bordeaux mixture prepared as is usually done for 

 spraying orchards. This was made according to the 1-to-ll 

 formula.! An arsenical poison, the gieen arsenite of copper, was 

 then added at the rate of about 1 lb. to 150 gallons, the amount 

 commonly recommended for spraying orchards. Mr. W. H. 

 Andrews very kindly analyzed this green arsenite and found 57.5 

 per ct. arsenious oxide and 25.2 per ct. copper oxide. This shows 

 that as an insecticide it is equivalent to good Paris green. 



An anther from a Ben Davis apple blossom was selected May 

 18 in the way already described. From the pollen which it fur- 

 nished a series of cultures was made as recorded below. This ifi 



here called Series I. 



Series I. 



Ifniriber of pollen 

 Cnltnre grains in the 



Mo. Medium. cultuie. 



9 2 per ct. aqueous cane sugar solution, 99 parts; mix- 

 ture A, 1 part 250 to 300 



10 2 per ct. aqueous cane sugar solution, 99^^ parts; 



mixture A, % part 125 to 150 



11 2 per ct. aqueous cane sugar solution, 89. 9S parts; 



mixture A, .02 part 125 to 150 



12 2 per ct. aqueous cane sugar solution, 99.99 parts; 



mixture A, .01 part 100 to 125 



As soon as these cultures were made, 5.45 p. m., they were 

 put into a room having a nearly constant temperature of about 



*This formula requires 1 lb. of copper sulphate, and the necess.Try 

 amount of lime, in making 11 gallons of the mixture. It is equivalent to 

 10.9 grams of copper sulphate for 1 litre of the mixture. 



