﻿ON THE GERMINATION OF THE POLLEN GRAINS OF 

 APPLE AND OTHER FRUIT TREES 

 J. Adams 



The following observations were made at Dublin, Ireland, in 

 1913, and were of a preliminary nature only. It was hoped to base 

 a much more complete series of experiments in 1914 on the infor- 

 mation gained in the previous year. Owing to unforeseen cir- 

 cumstances this was not possible, and as no opportunity for 

 continuing the investigation is likely to arise in the near future, 

 the results so far gained are given in the hope that others may 

 find them useful for comparison. 



There is much connected with the question of pollination that 

 is still obscure. For instance, it is known that a russet apple 

 produces seeds plentifully, while a Newton pippin contains only 

 a few seeds. In both cases the fruit is equally well developed. Is 

 there any relation between the number of seeds in the fruit and the 

 number of pollen grains that reach the stigma ? Presumably there 

 is, but one would imagine that the chances of pollination are the 

 same in both varieties. 



Failure of an individual flower to produce fruit may be due to 

 a variety of causes. The flower may not have been pollinated; 

 it may have been pollinated from another flower of the same 

 variety; it may not have been sufficiently pollinated, that is, the 

 stigma may have received only a small number of pollen grains; 

 it may have been pollinated too late, the stigma having ceased to 

 be receptive; the pollen grains may have been rudimentary and 

 incapable of germination; the temperature may have been too low 

 for the pollen grains to germinate; or the ovary or stigma may have 

 been injured by frost, either before the flower opened or subse- 

 quently. It seems obvious that a full understanding of all these 

 matters is of fundamental importance to all engaged in fruit growing 

 or seed production. 



The following observations relate to the germination of the 

 pollen grains in a cane sugar solution, their behavior when placed 

 131] [Botanical Gazette, vol. 61 



