AN EMBRYOLOGICAL STUDY OF LIMNOCHARIS | 
EMARGINATA. 
JOHN GALENTINE HALL, 
A 
ed 
(WITH PLATE IX) 
Limnocharis emarginata is of South American origin. The 
plants from which material was taken for study are growing 
in a large tank in the aquatic house at North Easton, under 
conditions that appear to be normal, and are certainly favorable 
for propagation, as is shown by the maturing of abundant seed 
from the self-pollinated flowers, and the large number of seed: ; 
lings that spring up spontaneously in the tank. ae 
_ The discrepancies in the comparative embryology of the 
group to which Limnocharis belongs, as represented by * 
work of Marshall. Ward, Schaffner, Campbell, and others 
seemed to justify careful examination of the present ™ 
_I shall give no account of the general morphology eee 
has described the development of the flower and of the tissue 
_ the growing point. ee 
The ovules in their general development follow p48 
the development of the ovules of Butomus umbe a eS 
__ by Marshall Ward. They arise as emergences | 
_ of the carpels without definite placental arra 
_ subsequent development is of the usual angi 
except the history of the embryo sac. Each Ml’ 
composed of two layers of cells, the inner being 
than the outer, and forming a considerable mass : 
_ apex of the ovule around the micropyle, as is the 
e and Zannichellia. From the outer coat, soon ae 
Se x rtain cells begin to develop into short hairs that 
_ @ rough appearance. Long before the seed 
__ form, the growth of the ovule is more rapid on © 
a and anatropy is already marked when the 
_ Coats make their appearance (jig. 4). 
Le : : 214 : 
