DEVELOPMENT OF OVULE AND FEMALE GAMETO- 
PHYTE IN GINKGO BILOBA 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 
XC 
IpA ELEANOR CAROTHERS 
(WITH PLATES V AND VI) 
Ovules were collected at Elyria, Ohio, at intervals of two weeks, 
from the first of May until the latter part of August 1905, and were 
sent to Chicago packed in wet cotton. In April 1906, additional 
collections were made. Having been freshened by a stay in a moist 
chamber, the material was killed and fixed in chromacetic or chrom- 
acetosmic acid and put up in paraffin. 
I wish to acknowledge my indebtedness to Miss A. M. STARR of 
Elyria, Ohio, for material, and to express my appreciation of the help- 
ful suggestions of Professor Joun M. Coutrer.and Dr. Cartes J. 
CHAMBERLAIN of the University of Chicago, where the work was begun. 
Megasporangium 
DEVELOPMENT.—The megasporangia are borne on the short spur 
shoots, which bear also a few leaves, the longer shoots producing 
leaves only. By the first of April the terminal buds of the spur shoots 
have begun to swell slightly, and after removal of the brown bud- 
scales, the green leaves can be seen, but ovules are not yet distinguish- 
able. Unopened buds collected the middle of April contain ovules 
which, with the stem bearing them, measure 2™™ in length. The 
ovules alone are only 0.25™™ long; they appear singly or in pairs 
at the end of leafless stems, and are pale cream color, while the leaves 
in the bud are bright green. Vertical sections (jig. 1) show the 
undifferentiated nucellus not yet wholly enclosed by the integument. 
The buds soon open, and the leaves and ovule-bearing stems 
increase greatly in length. Not all the buds are fertile, but in those 
which are, the ovule-bearing stems vary in number from one to six. 
The ovules are still pale cream color, but show a faint green tinge 
which deepens rapidly as they enlarge. The ovule stalks appear, 
not at the growing tip of the spur shoot, but around it, as do the 
Botanical Gazette, vol. 43] [x16 
