THE SCIENCE AND PRACTICE OF CROSS POLLINATION. 469 



However, Luther Burbank removes all but one-tenth of the blos- 

 soms on each tree and removes the stamens by the aid of a sharp 

 knife only. The petals also being removed by this operation, bees 

 are not apt to visit the flowers. He runs the risk of the flowers 

 being fertilized by pollen carried by the wind. He discards camel's 

 hair brushes also and applies pollen with the tip of the finger. I have 

 found it best to use this method of applying pollen where the quan- 

 tity is small. Sometimes the pistils can be dipped directly into the 

 pollen. Mr. Burbank, I understand, prefers to run the risk of fixing 

 the pedigree rather than lose the whole flower by the use of the 

 paper sack. 



In closing, it should be stated that pollination means the act of 

 applying pollen to the stigmatic surface of the pistil. If the pollen 

 ''takes," the flower is fertilized and sets seed. 



Mr. Lord : I heard Mr. Patten say he had experimented a good 

 deal in that direction, and that the removing of the petals was not 

 advisable; that most of the pollen was not potent on its own pistils; 

 that almost invariably foreign pollen was more potent than its own 

 pollen ; that emasculation had the tendency to disturb the setting, 

 and that the best way was to apply the pollen without emasculating 

 the flower. 



Prof. Hansen : In order to obtain exact scientific results the 

 only way is to emasculate the flower. You get surer results. The 

 only way is to take out the stamens, as I have stated. We simply 

 pull off enough of the petals, so they will not be in the way of the 

 work. 



Mr. C. H. True : Do you take the sack off again ? 



Prof. Hansen : As soon as a flower is fertilized. If you want to 

 experiment with that you can put a paper sack over a flower just as 

 it comes out, and the flower withers in a short time after the sack is 

 taken off. The florists apply that principle, taking the yellow heads 

 of anthers out of the lily because they stay fresher — waiting for the 

 pollen which never comes. 



Mr. Wedge : Do you consider it proven that the apple blossom 

 is self-sterile? 



Prof. Hansen : Some varieties are self-sterile, others self-fertile. 



The President : Does it make any difference whether the pollen 

 comes from every flower or from any flower from any part of the 

 tree? 



Prof. Hansen : It is found that some are self- fertile and some 

 are not, but the tendency of all of them is that the further apart they 

 are, the better. Thus, it is better for one variety to be fertilized by 

 some other variety than by other trees of the same variety. 



