242 The Botanical Gazette. [June, 
the development of the embryo-sac and its behavior previous 
to fertilization. The different species will be taken up in the 
order indicated above. 
Delphinium tricorne.—As is well known the ovules of Del- 
phinium arise as nipple-like protuberances from the infolded 
margins of the carpophyll. The epidermal and hypodermal 
rows of cells of the carpophyll pass uninterruptedly over this 
rudiment of the ovule. At the apex of the protuberance 
may be seen one or frequently more hypodermal cells distin- 
guishable by their larger size (fig. 2). The cell which ulti- 
mately gives rise to an embryo-sac will, for greater clearness, 
be spoken of in this paper as the initial cell of the embryo- 
sac, while the term mother-cell will be reserved for the lower 
one of the longitudinal row of cells arising from subsequent 
divisions of this cell. In the very young rudiment of the 
ovule (fig. 1) in a large number of cases the initial cell of the 
extended, the division of the lower cell preceded that of the 
upper, as will be seen in figs. 6 and 7. These divisions 
follow as a rule in rapid succession. The lower one of the 
