Campbell.—Studies on the Araceae. 15 
cells at the lower end. The two polar nuclei were present, 
and quite separate. The nucellus, while small compared to 
the size of the ovule, is larger relatively than in the other forms 
which we have considered. It is oval in form, and the lateral 
walls are composed of three or four layers of cells, while at the 
apex there are five or six layers of cells above the embryo-sac. 
In the youngest stages encountered (Fig. 35) the nuclei in 
the embryo-sac were much alike, of moderate size, and showed 
a large nucellus. There could be detected above the apex of 
the sac in some cases, what looked like the remains of tapetal 
cells, but whether such cells are always formed cannot now be 
stated. 
As the embryo-sac grows, it becomes somewhat longer 
(Fig. 36), but unlike that of most Araceae, it does not destroy 
the nucellar tissue completely, the lateral walls of the nucellus 
being perfectly evident for a long time after the embryo has 
begun to develop (Fig. 43). 
With the increase in the size of the embryo-sac, the egg- 
apparatus assumes its fully developed form (Figs. 37, 38). 
The egg-cell, as usual, is somewhat larger than the synergidae, 
and projects below them. It contains little granular cyto¬ 
plasm, and the nucleus, with its very large nucleolus, lies near 
the free end, close to the wall. The synergidae have much 
more densely granular contents, and the nuclei do not differ 
appreciably from the nucleus of the egg. 
The polar nuclei are of about the same size as the nuclei of 
the egg-apparatus, and probably remain separate until after 
the fecundation of the egg-cell. At any rate, in most of the 
cases examined, they were quite separate, although often in 
close contact (Fig. 41). They usually stain more uniformly 
than the other nuclei, but otherwise show no peculiarities. 
The Antipodal Cells. 
The antipodal cells in Lysichiton are very peculiar in their 
behaviour. At first they resemble the ordinary form, and 
their nuclei resemble closely in size and appearance those of 
the egg-apparatus. Soon, however, a difference is manifest. 
