160 BOTANICAL GAZETTE | MARCH j 
gives some account of the development of the ovule and 
embryo-sac in Arum, and Mottier has investigated the same _ 
points in Ariseema,™* but beyond these I have not been able to 
find any references to the embryo-sac in this very characteristic 
group of plants. As the work of Hofmeister had already — 
shown that the Araceze exhibit certain marked peculiarities of — 
the embryo-sac, it is remarkable that these plants have been 
overlooked in the more recent studies of the embryo-sac. The 
Aracee give many indications of being a primitive and general 
ized order, and no group of angiosperms is likely to furnish 
more important data as to the origin of the structures of the 
embryo-sac. 
In addition to the study of Lysichiton, the more important 
results of which are here given, more or less extensive studies 
have been made upon a number of tropical aroids, but these are 
not yet completed. The forms examined included species of 
Anthurium, Philodendron, and Dieffenbachia, collected 
Jamaica during the summer of 1897. : 
. The ovule of Lysichiton is very large (fig. 70) and chat : 
acterized by the massive basal part, which is extraordinarily 
large when compared with the nucellus. In the younger ovule | 
the outer integument is only slightly developed, but later | 
grows out beyond the inner one (fig. 75). The embryo-sat B 
deep-seated. So far as its early development has been follow 
it does not differ from that of the typical angiosperms, and - . 
are found the usual structures of the mature embry0-Sa6 1 : 
the egg-apparatus, polar nuclei, and three antipodal cells. Wh 
the embryo-sac itself is decidedly smaller than in Sparganu 
the egg-apparatus and antipodals are much larger. - . 
At first the nuclei of the cells of the egg-apparatus ie fet 
antipodal cells are much alike (fig. rr), but at the time © 
tilization (fies. 73, 74) the antipodal nuclei have ger : 
remarkably in size, while there has been little change engi 
of the egg-apparatus, although both the egg-cell and syns ] 
*MOTTIER, On the development of the embryo-sac in Ariscemé ment 
Bot. Gaz. 17: 258. 1892. 
