20 



THE POLLINATION OF PEAR FLOWERS. 



count. Ill tlie synopsis of results these cases are marked by tlie word 

 "estimated." Only the sum of the clusters and of the fruits under 

 each kind of bag for each tree were noted in this series. In the three 

 later series of experiments the number of clusters and of fruits in each 

 bag were noted. Specimen tables from my notebooks will be given in 

 the account of the Rochester series. 



The results of these Brockport experiments showed the trees to be 

 divided sharply into two classes, those which could fertilize themselves 

 and those which could not. On the trees of the latter class there was 

 only a single fruit under cover. This one developed under a mosquito- 

 net bag and was thought at the time to have been pollinated by a bee 

 through the meshes of the net. Later experiments have shown that 

 such a fruit may have been self-fertilized. 



On the varieties which fruited at all inside the bags, the percentages 

 of fruits were so nearly like those outside the bags that I was inclined 

 at the time to consider them nearly perfect self-fertilizers. The expe- 

 rience of the following year, however, caused this view to be changed 

 somewhat. The Angouleme, Seek el, and two unnamed varieties set 

 about as well inside the bags as outside. Sometimes the highest per 

 cent occurred in the bags and sometimes outside, but these dif- 

 erences were thought to be accidental. The Bartlett, Anjou, 01ai:)ps 

 Favorite, and Winter Nelis failed to set inside the bags, with the 

 exception of tlie single fruit above mentioned. 



These experiments demonstrate that some of the varieties are not 

 capable of fertilization when insects are excluded, but the reason for 

 tliis was not ascertained. Just what the insects could do for the flowers 

 was not shown. The question as to the real difficulty with these flowers 

 and their difference from those capable of setting fruit when insects 

 were excluded came up for an ansAver. Some decided structural or 

 physiological difl'erence, such as the death of the stigma before the 

 anthers of the same flower have shed their pollen, or the impotency of 

 pollen to stigmas of the same flower were thought of as x>ossible 

 explanations. In case cross-fertilization were necessary, the question 

 arose whether a very near kind of pollen Avas sufficient, such as from a 

 different flower on the same branch, or whether that of a more remote 

 character was required, such as from another tree. 



The results of the work on the trees at Brockport will be found in 

 the synopsis, together with the other work on the same varieties. 



SERIES II. — EXPERIMENTS AT CHESTNUT FARM, VA. 



Account of the Old Dominion orchard. — In February, 1892, the writer 

 visited the large i)ear orchard of the Old Dominion Fruit Company at 

 Chestnut Farm, which is located near Scotland, on the James River. 

 The orchard consisted originally of about 22,000 standard Bartlett 

 p(nir trees. It was planted seventeeii or eighteen years ago, tlie 



