The Ohio ^J\(^aturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State University, 

 Volume IV. JUNE, 1904. No. 8. 



TABLE OF CONTENTS 



York— The Embryo-sae and Embryo of Neluinljo 167 



OsEOEX — Formal Opening of the Lake Laboratory Bnilding 177 



Kellerjian and Jennings— Flora of Cedar Point 186 



Kellerjian— Flora of Hen and Chicken Islands, 190:-! 190 



ScHAFFNER— The Jacket Layer in Sassafras 192 



FiiANK- Meetings of the Biological Club 193 



THE EMBRYO=SAC AND EMBRYO OF NELUMBO.^^^ 



Harlan H. York. 



Siuce the publication of Lyon's studies on Nelunibo and Cook's 

 work on Castalia and Nymphaea, the systematic position of the 

 Nymphyaeaceae has again become a prominent question. Owing 

 to the variety of opinions held' ,in regard to the classification of 

 this group, it was thought desirable to continue the study of the 

 life history of Nelumbo lutea, s^lhoi-^g'h this plant has been 

 described more or less completely a|||umber of times. 



Material was collected during July-and August, 1902, in San- 

 dusk}' Ba}-, near the Ohio State University Lake Laboratory, at 

 Sandusky, Ohio. Flemming's stronger and weaker solutions 

 and chromo-acetic solution were used as killing and fixing 

 agents. On examining the ovules, it was found that in most 

 cases the tissues had not been properly penetrated b}' these fluids. 

 In the summer of 1903 more material was collected, near the 

 place already mentioned, which was killed and fixed in Kleincn- 

 berg's picro-acetic and picro-sulphuric solutions and was found 

 to be preserved in good condition. The ovules were passed 

 through the alcohols, imbedded in paraffin, and serial sections 

 were cut 10-12 mic. thick. For staining several reagents were 

 used : Delafield's heamotoxylin, Heidenhain's iron alum haemo- 

 toxylin, analiu safranin and gentian violet. All of these stains 

 were successful, the last named stain giving the best results. 

 Considerable difficulty was experienced, in that a great many 

 ovules had failed to develop embryo-sacs and others had not been 

 fertilized. Quite a large number of slides were prepared and 

 most of the points mentioned were observed a number of times. 



This work was commenced under the direction of Prof. Mel. 

 T. Cook in the De Pauw University Botanical Laboratory and 



* Contributions from the Botanical Laboratory of Ohio State University. XVII. 



