344 THE NEW GARDENING 



get in. When the buds opened the bags were temporarily 

 removed, and the flowers immediately crossed with their 

 own pollen by the use of a brush. The bags were replaced 

 at once and kept on until the fruit (where it formed) had 

 begun to swell, so that there might be no suspicion of 

 foreign pollen intervening. 



With this treatment the varieties Victoria, The Czar, 

 Pershore, White Magnum Bonum, Prince Englebert, 

 Denniston's Superb, Early Transparent Gage, Purple 

 Gage and a Damson set a good crop, and are therefore 

 self -fertile in the fruit-sense. 



On the other hand, Hist on Green Gage, Early Orleans, 

 Late Orange, Sultan, Kirke's, Coe's Golden Drop, Reine 

 Claude d'Althann, Green Gage, Blue Imperatrice, Late 

 Transparent and Washington did not yield fruit, showing 

 that they are self-sterile in the fruit-sense, and need 

 foreign pollen to be fruitful. 



The important variety Rivers's Early Prolific has 

 been found fruitful up to a point when kept to its own 

 pollen, but to be more productive when crossed with 

 extraneous pollen. 



In some cases of self-sterile varieties the flowers en- 

 closed in the bags do not set fruits at all, in others fruit 

 forms, swells up to the size of a Pea and then falls ; in 

 both cases the result is the same failure to crop. 



The deduction that the practical man will draw from 

 the foregoing is that since cross-pollination is vital in 

 some cases it is probably good in all, and he will provide 

 for facilitating it by keeping bees if his neighbours do 

 not obligingly do so. 



He will not grow very large blocks of one variety with- 

 out intermixing a few trees of other sorts for supplying 

 fresh pollen. 



