22 
successfully pollinated both before daylight and after nightfall, 
artificial light having to be used to enable the pollinator to see in 
each instance. The results of the test indicate that pollination may 
be begun as early and continued as late as is convenient, the hour 
of pollination having no effect on the number of pods setting, but 
as the sepals and petals begin to close around the lip in the early 
afternoon, the morning hours permit easier and more rapid work 
than the afternoon, and for this reason work should be begun as 
early as possible. 
Forty blossoms pollinated in the late afternoon after a rain all 
set, showing that a rain prior to pollination need do no damage 
since the essential organs are well protected by the lip. 
Comparative dropping of hand-pollinated blossoms and those not 
Jiand-pollinated . — The 200 blossoms of the above test were com- 
pared with 200 which were not hand-pollinated, with the result that 
92.5 per cent of the hand-pollinated blossoms remained clinging 
to the ovary after an interval of one week, while only 1.5 per cent 
of those not hand-pollinated remained. No blossoms of either lot 
had dropped by 4.30 p. m. of the day following opening, but of all 
blossoms which dropped within a week of opening more than 94 
per cent had dropped by noon and nearly 98 per cent by 4.30 p. m. 
of the second day following the opening of the blossom. The pol- 
linator thus sees within a few days after pollinating just which pods 
have set and so is enabled to discontinue pollinating as soon as the 
desired number has been obtained, there being practically no chance 
fertilization. 
Pollination of early opening v. late opening blossoms of a cluster. — 
To determine whether the earlier opening blossoms of a cluster possess 
an advantage over those which open later, measurements were 
taken of the length of the pods in 100 clusters which had developed 
two pods each. In 57 instances the longer pod had developed from 
the earlier blossom, in 8 the pods were of the same length, and in 
35 the longer pod had developed from the later blossom. 
Heavy v. light pollination. — With few crops is the grower able to 
definitely determine the size of his harvests. Yet within certain 
limits this is true of the vanilla grower. As the vanilla vine pro- 
duces a much greater number of blossoms than it is able to develop 
pods, it lies with the pollinator to say how many pods shall be pro- 
duced. With the object of determining something of the effect on 
the size of the pods of heavy and light pollinations, the following 
experiment was undertaken with the 1917 crop in the station 
vanillery: 
As the plants differed in amount of vine growth, the production of 
a definite number of pods per plant would have imposed a very 
uneven demand on the different plants since what for some would 
have constituted a yield of reasonable quantity for others would 
