WESTER: POLLINATION EXPERIMENTS WITH ANONAS 537 
open sufficiently twenty-four hours before the shedding of the 
pollen to admit the entrance of small insects to the stigmas. 
Practically all the flowers shed their pollen early in the morning 
before sunrise; only rarely has it been noted in the afternoon. 
This is accompanied by a strong, rather disagreeable odor and it is 
highly probable that the pollination is performed by nocturnal 
insects. There is no evidence that the pollination of this species 
is performed in the manner indicated by Morong in Anona corni- 
folia St. Hil., the construction of whose flowers is very similar, 
and the results obtained in the pollination work show that the 
pollen must be conveyed from one flower to another in a less 
advanced stage of development. 
In this connection it is interesting to note that the observations 
on Anona cornifolia St. Hil. in Paraguay by Morong, to which 
my attention was directed a few months ago, led him to the con- 
clusion that this species also is entomophilous. 
“The stigmas lie . . . as far as I could judge entirely out of 
reach of the pollen by any action of the organs themselves. I 
found, however, that the pollen was very plentiful and that a pin 
thrust through the anthers obliquely would carry its grains to 
the stigmas. There seemed in the older flowers to kh ae 
that this operation is performed by insects, and I o the 
conclusion that the an must always depend for Pecan 
upon insect agency.’ 
It would appear that Morong considered the stamens and 
pistils synchronous, although it is not evident that this conclusion 
was arrived at after investigation. That the flowers might have 
been dichogamous seemingly escaped him. 
In the course of the pollination experiments of the cherimoya 
and custard apple a very interesting observation of the retardation 
of the development of a large number of fruits was made. Some 
cherimoya fruits developed without interruption from the time 
of pollination and matured in September, while a number remained 
stationary in size, about 8 mm. in diameter, until after July 25, 
when they suddenly began to increase in size and matured in 
October and November. 
The flowering season of the custard apple begins in the latter 
*Morong, T. Ann. N. Y. Acad. Sci. 7: 47- 1892. 
