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POLLINATION IN ORCHARDS. 

 By F. J. CHITTENDEN, F.L.S. 



I AM venturing to bring the question of pollination in orchards before 

 this Association, because, in the first place, it is one of extreme economic 

 importance in the fruit-growing industry, since it touches one of the 

 fundamental points for consideration in planning the planting of an 

 orchard ; and, in the second place, the problems its phenomena raise 

 include many of deep biological importance. Like so many of the 

 questions the practical man has at present to solve by empirical methods, 

 and which await scientific investigation, it touches more than one side 

 of biological science. 



Historical note. Swayne was the first, in 1823, to demonstrate by 

 experiment that certain varieties of pears were self-sterile, i.e. required 

 the intervention of pollen from another variety in order to cause fruit 

 production. Peaches, old gardening literature shows, were thought to 

 require pollen of other varieties, but experimental evidence seems lacking 

 in regard to this fruit. The matter, although set out very clearly by 

 Swayne, was apparently lost sight of until about 1890, when Waite 

 re-discovered it for pears in America, and later found the same thing 

 was true of apples. Considerable attention has been, and is being, 

 devoted to the problem with these and other fruits in America, and to 

 a less extent in Australia and other of our great fruit-producing colonies. 



Our own experiments, begun at Chelmsford in 1902, confirmed 

 Waite's observations, and clearly established the fact that a large pro- 

 portion of our commonly grown varieties of apples and pears failed to 

 set fruit unless pollen from some other variety was placed upon the ripe 

 stigma. More recently Backhouse, and, later, Sherrard, has shown that 

 our varieties of plums fall into two more or less distinct groups of self- 

 sterile and self-fertile types. Cherries, peaches, nectarines, and probably 

 grapes also, apparently show the same phenomena. Hooper's experi- 

 ments at Wye are confirmatory. Some work has also been done by 

 continental biologists upon the problem, but especially by Ewert in 



