| 
The embryo-sac of Alisma Plantago.' 
JOHN H. SCHAFFNER. 
WITH PLATES IX AND X. 
The embryo-sac of angiosperms still presents an inviting 
field for research. There seem to be many variations in the 
general processes which occur in it, and most of the observa- 
tions on the finer structure need confirmation. Especially in 
regard to the real meaning of the conjugation of the polar 
nuclei, and what is represented by the antipodal cells, does 
there still seem to be much obscurity. It was for the pur- 
Pose of making a preliminary study with a view for further 
investigation later, that the following work on the embryo-sac 
of Alisma was undertaken. 
The embryo-sac of Butomus umbellatus L.. was described 
by Vesque? in 1878, and later by H. Marshall Ward,* who 
also made a few observations on Alisma Plantago L., which 
agreed in general with those on Butomus. The development 
h 
a hitherto not been confirmed. aad 
iz Y material was collected on July 30, 1895, and killed ina 
seas beetic acid solution: acetic acid 0.7 per cent., chromic 
pie 0.3 per cent., water 99 per cent. All the sections were 
Th Schy imbedding in paraffin and staining on the slide. 
T € principal stains used were anilin-safranin and acid fuchsin. 
Contributi iversity of Michi 
m on from the Botanical Laboratory of the University of Mic pi 
des Se SpPement e sac embryonnaire des phanérogames angiospermes. fam: 
ic. Ot VI. G6: 237-285, 1578. . 
Lian Soe Mons to our enoated ou the embryo-sac in angiosperms. Jour. 
‘Do, Ot. 17: 519-546. 1880. : ische 
Abbandemicklung des Keimes der Monokotylen und Dikotylen. genes 
(Bonn, ngen aus dem Gebiet der Morphologie und Physiologie 1: —- : 
9g ee Etudes sur la fécondation, etc. Ann. des Sci. Nat. Bot. VII. 14: 
. Z. 
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