62 BOTANICAL GAZETTE [JANUARY 
In undertaking this investigation I had hoped to find abun- 
dant embryos and germinating seeds, in order to determine the 
comparative morphology of the parts of the plant. But as few 
were found I can make little addition to the statements of other 
writers. When the seed coats burst the cotyledon appears fist, 
and is so folded that it encloses the young stem. An absorbing 
organ remains in contact with the food material of the seed. 
The basal and nodal regions of the shoot soon become differen 
tiated, and quite early there are developed the pouches in which 
are the new vegetative fronds. The energy of the plant now 
seems to be directed toward this new frond rather than to the 
embryonic organs, since all of the latter very soon disappear. 
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ECOLOGICAL NOTES. 
In this connection I need but to mention the numerous 
large air spaces for aeration and floating, and the chloroplastids 
which have such great power of adjusting themselves to the : 
light, to recall two prominent ecological adaptations of this — 
plant. 
Water and pollination.— It will be remembered that most water 
plants, e. g., Naias, Vallisneria, and Elodea, have adaptations | 
for securing pollination which are especially suited to their 
water environment, while the structures of the ovule, so far be 
reported, are rather normal. In Lemna we seem to have 4 plathe 
which has exchanged a land for a water habitat, and in So doing t 
has not succeeded in working out such effective devices for pol 
lination as have the real water plants. This might addaddi- 
from terrestrial forms. The terrestrial method of pollination 
seems to have proved almost a failure in the new conditions, 
this may be the ultimate cause for the more or less complete q 
disorganization of the structures of the embryo sac. L 
Winter buds.—There has been much discussion with referen® 
