426 REPORT OF THE HORTICULTURAL DEPARTMENT OF THE 
cause the loss of more fruit than any other of the climatal agencies. 
The damage is done in several ways. The most obvious injury, 
and the one most often noticed by fruit growers, is the washing 
of the pollen from the anthers. The secretion on the stigmas, so 
essential to the proper germination of the pollen, also is often 
washed away or becomes so diluted that the pollen does not germi- 
nate. It is probable that the chill of rainy weather decreases the 
vitality of the pollen and an excess of moisture often causes pollen 
grains to swell and burst, thereby destroying their vitality. Quite 
as important as any of the above considerations, possibly more 
so, is the fact that rain prevents bees and insects from carrying 
pollen and must effectually prevent its distribution by wind, if wind 
doe distribute the pollen of fruits. 
Weather conditions, and especially rain and a humid atmosphere, 
have much to do with the development of parasitic fungi. A wet 
May in New York brings an abundance of fungi of several species, 
which may destroy or injure blossoms and prevent the setting of 
fruit. Whule rain is the chief weather condition, it is not the only 
one that must be taken into consideration in this connection. With 
some fungi heat is a strong factor and with others, cold. Cloudy 
weather, too, or a humid atmosphere without rain will give favor- 
ing conditions for the growth of fungi. 
In the long continued cold, rainy weather during the blooming 
time of 1907, there was an excellent opportunity to observe the be- 
havior of blossoms on the Station grounds. Not only did such 
weather hinder the transferrence of pollen, but the pollen did not 
form in the anthers in normal quantities and was not expelled from 
them. The secretion in the stigmas seemed diluted and watery, 
so that the pollen grains, either because of such dilution, or in con- 
sequence of the cold, or because of both, did not germinate properly. 
If as Ewert! holds, pollination is not absolutely necessary for 
some varieties of apples and pears it is still true that cold, rainy 
weather is most unfavorable for the setting of these apples quite 
eside from its effects in preventing the impregnation of the ovary. 
Such weather prevents the development of the young fruits whether 
fertilized or unfertilized. In the latter case the young fruits do 
not have the stimulus of an impregnated ovary to assist in over- 
coming the deleterious effects of the unfavorable weather. 
The average rainfall for May in the different parts of New 
7 Ewert. Blutenbiologie und Tragharkeit unserer Obstbatime. Landw. Jahrb., 
35: 258-287, pls. 2, 1906. 
