382 ReEporT OF THE HORTICULTURAL DEPARTMENT OF THB 
SERIES VI. 
Number Per ct. 
of pollen Number of ger- 
Culture ‘ grainsin of germi- mina- 
No. Medium, culture. nations. tion. 
56 2 per ct. aqueous solution cane sugar.. 119 90 76 
57 Copper arsenite and lime’ and a 2 per 
ct. aqueous solution cane sugar...... 161 0 90 
58 Mixture C, * part; 2 per ct. aqueous 
solution cane sugar 9943 parts..... oth 15 14 93 
59 Mixture C, 1 part; 2 per ect. aqueous 
solution cane sugar 99 parts?......... 
61 Mixture C, 2 parts; 2 per ct. aqueous : 
solution cane sugar 98 parts......... about 300 0 0 
The cultures were kept in a moist chamber in a room at about 
81° F. till 2:45 p. m., of July 30, or about 3} hours. It was then 
found that 76 per ct. in the culture No. 56 had germinated and 
93 per ct. in No. 58. No germination was found in any of the 
other cultures. 
Twenty-one hours after the cultures were made they were dis- 
carded because no further germination took place. 
SUMMARY OF RESULTS WITH POLLEN CULTURES... 
In the cultures with apple pollen in cane sugar solutions in 
water alone (see Series II) the pollen tubes seemed to do better 
in a 2 per ct. solution than in either a 5 per ct. or a 10 per ct. 
solution. They also grew better in the 2 per ct. sugar solution 
in water than in pure water. For these reasons the media for 
the cultures in Series I, III, IV, V and VI were made to con- 
tain a 2 per ct. aqueous solution of cane sugar. 
Series I.—Culture media contained cane sugar solution im He 
Bordeaux mixture and green arsenite of copper.—In this series 
pollen from Ben Davis apple was used. Only from one-third to 
one-half of the pollen grains germinated in the 1 per ct. mixture 
A, culture 9, which contained but 100 parts in 10,000 of an 
ordinary mixture used in spraying orchards, the remaining 9,900 
parts being a weak solution of cane sugar in water. The tubes 
from the pollen which did germinate grew slowly and were 
dwarfed and abnormal in shape. 
1Prepared as for cultures No. 20, see p. 379. 
2Destroyed by accident before last examination was made. 
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