4 The Ohio Naturalist, 
PUBLISHED BY 
The Biological Club of the Ohio State University. 
Volume III. JUNE, 1903. No. 8. 
TABLE OF CONTENTS 
Burr— E mbryology of Vallisneria 430 
Swezey— Parasites on Certain Fulgorid;e 447 
Foulk— The Society of Sigma Xi 451 
Jknxings-Griogs— M eetings of the Biological Club 452 
THE EMBRYOLOGY OF VALLISNERIA SPIRALIS.* 
Harriet G. Burr. 
The material for this study was gathered in Sandusky Bay in 
July and August, 1902. It was killed in chrome-acetic acid, 
preserved in 70 per cent, alcohol, imbedded in paraffin, cut on a 
Minot rotary microtome, and stained in analin safranin and gen- 
tian violet, and also in Heidenhain’s iron-alum-haematoxyliu. 
For the development of the embryo-sac the former was the best, 
and the latter for the staminate flowers. For the embryo, either 
stain gave satisfactory results. 
The sections were cut 8-12 microns thick, the staminate flowers 
transversely and the carpels longitudinally. The older ovules 
were removed from the ovulary and imbedded separately. This 
was necessary on account of the mucilaginous material which 
was contained in the carpels. 
The work was carried on at Ohio State University under the 
direction of Prof. J. H. Scliaffner to whom I am greatly indebted 
for assistance and suggestions. 
The carpellate flowers are borne on a long scape with a tubular, 
one- flowered spathe. The perianth has a linear tube adnate to 
the one-celled ovulary. There are three small petals, and three 
stigmas which are short and broad. The ovules are numerous 
and orthotropous, borne one the ovulary wall. The staminate 
flowers are numerous, nearly sessile, on a conic receptacle, 
enclosed in a spathe which is borne on a short scape. The per- 
ianth is three-parted, the petals being very small. The androe- 
cium (Fig. 9) is a two-parted structure which may be regarded 
as two stamens united at the base, or a single stamen, as described 
by Engler and Prantl. If the former view be held, the anthers 
Contributions from the Botanical Laboratory of Ohio State University. XIII. 
