1909] MCALLISTER—EMBRYO SAC OF SMILACINA 201 
undergone division. He concludes that in these cases the course of 
development is abbreviated, so that there is no formation of reduced 
cells which are to be immediately absorbed, as is the case in many 
other species. According to this view the heterotypic and homeotypic 
divisions are transferred to the early stages of development of the 
gametophyte. 
The term “macrospore” or “megaspore” is frequently loosely 
used by the supporters of this view in reference to the cell which 
develops into the embryo sac, whether it be the young embryo sac 
itself, or one of the daughter cells, or one of four granddaughter cells 
which have been formed by the reduction divisions. 
From the evident homology of the nuclei of the first two divisions 
of the embryo sac mother cell of the lilies with the microspores, as 
Suggested by the discoveries of GUIGNARD, STRASBURGER, OVERTON, 
and also later investigators, the obvious interpretation of their nature 
is that they are megaspores. According to this view the reduction 
divisions may be regarded as the sole criteria of spore formation. 
STRASBURGER (26) further says, in reference to the significance of 
the number of divisions which intervene between the embryo sac 
mother cell and the completed embryo sac, with its egg: “That the 
number of these intervening divisions is not of primary importance is 
Proved by the fact that the number is not always the same: thus in 
Lilium and Tulipa there are but three; in Ornithogalum, Com- 
melyna, and species of Agraphis, there are four; in yet other cases the 
number jis greater than five. ... . ” 
Smilacina stellata, the species which I have studied, is a member of 
the order Convallariaceae. The data as to the morphological relation- 
ships of the genus Smilacina are scanty and in part contradictory. The 
order Convallariaceae is retained by ENGLER and PRANTL under the 
sroup Asparagoideae, but the nature of the relationship of the group 
'o the other orders of the Liliales is not very clear. The other mem- 
bers of the Convallariaceae whose embryo sac development has been 
Studied are Convallaria, Paris, and Trillium. 
Convallaria majalis has been investigated, as to the development 
of its embryo sac, by WIEGAND (29). He reports that the embryo 
‘ac mother cell divides to form two fully separated daughter cells, 
the outer of which is the larger. The nuclei of both of these cells 
