The Ohio T\[^aturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State Uni'versity, 

 Volume VI. JANUARY, 1906. No. 3 



TABLE OF CONTENTS 



Tillman— The Embryo Sac and Embryo of Cucumis sativus 423 



Hubbard— Physiography and Geography— Their Relations, Differences and Essential 



Fields 431 



Nelson— A Note on the Occurrence of Sex Organs in Aelosoma 435 



BuEGESs— A Preliminary Report on the Mosquitoes of Ohio 438 



Kellerman. YiiRK AND Glea SON— Annual Report on the State Herbarium for the 



Years 1903, 1904, and 190i 441 



DUKY— How to Collect Stylopidae 443 



Sterki— Some Notes on Martynia 444 



Miller— Classification and Mapping of the Lower Ordovician in Kentucky 447 



HiLLiG — A New Case o f Mutation 448 



Sterki — A Few General Notes and Remarks with Respect to the Land and Fresh Water 



Mollusca 449 



Schaffner — Additional Observations on Self-pruning 450 



Metcalf— Meetings of the Biological Club , 451 



THE EMBRYO SAC AND EMBRYO OF CUCUMIS SATIVUS.* 



Opal I. Tillman. 



Before the present investigation was begun practically no 

 detailed morphological work had been reported on the Cucurbi- 

 taceae and as there has been much doubt concerning the sys- 

 tematic position and relationship of the plants constituting this 

 family it seemed to offer an interesting and profitable field for 

 research. 



Cucumis sativus was taken by the writer for special investi- 

 gation as a representative of the group but before the results of 

 the work could be published Kirkwood reported (3.) the results 

 of his work on "The Comparative Embryology of the Cucurbi- 

 taceae." In this paper he considers seventeen species, but not 

 Cucumis sativus. Longo has worked on the behavior of the 

 pollen tube (1.) and in his more recent paper (2.) he reports an 

 interesting condition of the pollen tube in Cucurbita pepo which 

 is practically the same as occurs in Cucumis sativus. 



Material for study was collected during the summer and fall, 

 killed in chromo-acetic acid, passed through successive grades of 

 alcohol and preserved in 70%. Serial sections were cut 10-12 

 mic. thick, 10 mic. being the usual thickness. The stains used 



^ * Contributions from the Botanical Laboratory of the Ohio State University, XXII. 



