382 KiEPORT OF THE HORTICULTURAL DEPARTMENT OF THE 



Series YI. 



Number Pnr ct, 



of pollen Kumber ofger- 



Cnltnxe , grains in ol germi- miua- 



^o. Medium. cnlttire. 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 



58 Mixture C, k'o part; 2 per ct. aqueous 



solution cane sugar Q9V, parts ' 15 14 93 



59 Mixture C, 1 part; 2 per ct. aqueous 



solution cane sugar 99 parts' 



61 Mixture C, 2 parts; 2 per ct. aqueous 



solution cane sugar 9S parts about 300 



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 3i 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 eugar. 



Series I. — Culture media contained cane sugar solution in water, 

 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 au 

 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. 



1 Prepared as for cultures No. 20, see p. 379. 



2Destroyed by accident before Inst examination was mnde. 



