luj. LIBRARY]^ 



The Ohio ^atim 



PUBLISHED BY 



The Biological Club of the Ohio Slate Uni'versity. 

 Volume III. JUNE. 1903. No. 8. 



TABLE OF CONTENTS. 



Birr— Embryology of Vallisneria 439 



SwEZEY— Parasite.s on Certain Fulgorida^ 447 



Foui.K— The Society of Sigma Xi 451 



Jenxings-Griggs— Meeting.'; of the Biological Club 4'V2 



THE EMBRYOLOGY OF VALLISNERIA SPIRALIS.* 



H.\RRiET G. Burr. 



The material for this study was gathered in Sanduskj^ 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-haematoxylin. 

 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 ovular}^ 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. Schaffner 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 max- 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 



-Contribution.s from the Botanical t,aboratory of Ohio State University. XIII. 



