JAN 3 0 1906 
The Ohio If^aturalist, 
PUBLISHED BY 
The Biological Club of the Ohio Slate Unwersity. lie 
NEV 
Volume VI. JANUARY, 1906. No. 3 0OT 
“ QAl 
TABLE OF CONTENTS 
Tillman— T he 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 Aelo.soma 435 
Burgess — A Preliminary Report on the Mosquitoes of Ohio 438 
Kellerman. York and Gleason— .V nnual Report on the State Herbarium for the 
Years 1903, 1904, and 1905 
DURY— How to Collect Stylopidae 443 
Sterki— S ome Notes on Martynia 444 
Miller— C las.sification and Mapping of the Lower Ordovician in Kentucky 447 
Hillig— A New Case of 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— M eetings 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 Embryolog}^ 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. 
