(342) 
displaces the surrounding tissue of the nucellus. As the 
cavity in the nucellus expands the endosperm keeps pace with 
it, forming always a thin layer closely applied to the sterile 
tissue. The displacement of the tissue of the nucellus, how- 
ever, is mainly in the direction of the chalaza, and even when 
the embryo is comparatively small (fg. 32) the nucellus is 
penetrated by a thin string of endosperm which reaches 
almost to its base. When the embryo is older ( figs. 33, 34) 
this string of endosperm becomes more evident, but the lateral 
tissue of the nucellus, that is the tissue along its sides, is only 
slowly dissolved. The nucellus and in fact all parts of the 
ovule enlarge rapidly, so that at the stage of embryonic de- 
velopment represented by figure 32, which is comparatively 
early, the ovules have already enlarged to many times their 
size at the time of fertilization, and the outer integument has 
already undergone considerable modification in the way of 
thickened cell-walls. 
Apodanthera 
The material available for the study of this form was 
somewhat fragmentary, consisting mainly of fruits and seeds 
in rather advanced conditions. The early stages showing the 
development of the gynoecium and the origin of the sporog- 
enous tissue were entirely lacking. Figures 35-43 repre- 
sent fairly well the conditions observed in this material, which 
include mature embryo-sacs and embryos in various stages of 
development. 
The development of the ovary in Afodanthera appears to 
conform to the usual type so far as could be determined from 
the material at hand. Each placental flank bears a row of 
ovules which at the time of fertilization lie with their micro- 
pyles directed outward. t this time the placentae have 
entirely fused where they come into contact at the center. 
The ovules at this stage are nearly circular in longitudinal 
section, the outer integument being thick (about one sixth 
the diameter of the ovule), while the inner integument is but 
a thin layer, two or three cells in thickness. 
