New York AGRICULTURAL EXPERIMENT STATION. 399 
is liberated before the stigmas become receptive, but a good por- 
tion of the pollen remains on the anther and is gradually released 
even some time after the pistils are in condition to be fertilized. 
Grape pollen is notably resistant to the ordinary influences of 
decay,! and it can be readily seen how in an inconspicuously 
flowered plant like the grape, where insect visits might not be 
so numerous as would be desired for pollinating purposes, keep- 
ing qualities on the part of the pollen grains would be so valuable 
a factor that it could not be sacrificed even for so important a 
consideration as cross-fertilization. The question as to whether 
there may not be a lack of affinity between the pollen of a self- 
sterile grape and its own pistil will be difficult to settle con- 
clusively, and yet the foregoing evidence seems to show that 
such lack of affinity does not exist, since poor pollen was found 
in all those varieties examined of the self-sterile class, and only 
in those of this class. Furthermore, the phenological evolution 
referred to, if this be accepted as a fact, is strong negative proof 
that lack of affinity does not exist, for if any of the original 
hermaphrodite forms had possessed that quality by which pollen 
of a certain plant is impotent on the pistils of the same plant at 
the same time being good on all others then there would have 
been no cause to produce the staminate and pistillate forms of 
to-day, for cross-fertilization would have already been assured. 
The economic bearing of these results is quite apparent. It 
has heretofore been necessary in order to determine whether a 
certain variety of grape was self-fertile or not to sack certain 
clusters before the blossoms opened and see if any fruit set with 
the pistils thus protected from the entrance of outside pollen. 
‘These operations, besides taking considerable time, are subject 
to all the accidents which are apt to occur when such delicate 
work is being done in the field. The pressure of the sack may 
destroy the pistil or the sack itself may be knocked off by per- 
sons or storms, and there is always the possibility of the acci- 
dental entrance of other pollen. In careful experiments all this 
is provided for by duplicating the sacks until the chances are 

1Bul. No. 157, page 438. Pollen was germinated at this Station this year three. weeks after 
it had been gathered in California. 
