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LIFRART 
NEW YORE 
RoOTANICAL 
i+x#DtUuN 
THE ENDOSPERM OF UTRICULARIA 
By Rosert B. WYLIE AND ALICE E. Yocom 
Department of Botany, University of Iowa 
Studies related to seed production remain among the funda- 
mental lines of botanical investigation. The potential value of 
such information in relation to plant breeding and crop pro- 
duction calls for critical and, if need be, repeated investigation 
of all problems that may shed any light on the structures and 
activities related to reproduction in higher plants. Interest is 
stimulated also because of insufficient information concerning 
some of the events taking place in the embryo-sac, and uncer- 
tainty as to the precise function of some of the parts concerned. 
The general uniformity of events centering about seed pro- 
duction in Angiosperms is undoubtedly significant, though capa- 
ble of various interpretations. The practically uniform be- 
havior of both the male and female gametophytes in such dif- 
ferent groups as Monocotyledons and Dicotyledons still seeks 
explanation. These divisions of the great Angiosperm group 
are at present widely divergent in many respects, yet the struc- 
tures immediately related to their reproduction are almost 
identical. It may be, as would at first appear, that such condi- 
tions point to a common past and suggest that adaptation is as 
yet incomplete. It is hardly conceivable though that any known 
antecedent structure so resembled the eight-nucleate embryo-sae 
as to dominate its present behavior. If inherited tendencies pre- 
vail why not a larger development within the nucellus as in 
Gymnosperms? On the other hand why is it not reduced to 
simply an egg? 
There must, then, be hindering factors on the one hand 
to inhibit marked development of the female gametophyte of 
the Angiosperm. On the other hand further reduction seems to 
be inconsistent with its successful operation; accessory parts 
seem necessary aids to fertilization and nutrition of the early 
stages of the embryo. Constancy of the gametophyte is a com- 
Contributions from the Iowa Lakeside Laboratory, No. 49 
3 
