and Affinities of Trapella. 91 
appendage is found with sparing, highly vacuolated protoplasm, 
and with nuclei much lobed, and showing a tendency to frag- 
mentation (Figs. 34, 34 a). As the ripening seed and embryo- 
sac increase in size, the appendage becomes relatively less 
important, as in Fig. 32, and especially in Fig. 35, where it is 
but an appendix to the ripe seed. 
In favourable preparations, what I take to be the dwindled 
remains of the two proximal cap-cells (Fig. 33, c 1 and c 2 ) may 
still be made out. These flattened remnants in older stages 
are not to be found. These dwindling cap-cells retain still 
their deliquescent walls— in contradistinction to those of the 
endosperm. In later stages, also, the basal parts of the appen- 
dage become, to a certain extent, sheathed by a layer of 
endosperm-cells — as it were a lip growing over it (Fig. 34). 
This arises only later on, and is perhaps due to the still active 
elongation of the endosperm, after the tip of the appendage 
has reached its furthermost limit. Figure 34, showing this, is 
taken from a section at right angles to Fig. 33. In it the 
appendage appears to consist of a single cell, an appearance 
due to the partition-wall being parallel to the plane of the 
section. This sheathing by endosperm-cells is not generally 
equal on all sides, but unequal as in Fig. 34. 
This appendage— unparalleled so far as I know — is all of a 
part with the sequence of events in this strange plant. For 
here is a plant, no doubt descended from forms with superior 
ovary, in which the only ovule which continues to develop, for 
some reason elongates downwards with great rapidity, and has 
in course of time brought about the considerable invagination 
of the ovary to accommodate it. It is not wonderful then that 
the plant has, pari passu , seized on a means for supplying its 
developing endosperm, and ultimately of course the embryo, 
with food-material. It has been the apical cap-cell, which 
normally dwindling to nothing, in Trapella has become 
modified into this embryonic absorptive organ. 
As the seed ripens if is to be noticed that the wall of that 
part of the ovary which is above the insertion of the calyx- 
limb, and which before fertilization was thick and very 
