1 88 Phillips , — The Development of the Cystocarp 
Delesseria ruscifolia, Lamx. 
D. ruscifolia is undoubtedly closely allied to D. Hypoglossum , 
with which indeed it seems to have been confounded until 
Turner (’02) pointed out the distinguishing characters. In 
its dark-red colour D. ruscifolia resembles D. sang'uinea 
rather than D. Hypoglossum. Its segments are oval or oblong 
rather than lanceolate, as in D . Hypoglossum ; a lateral 
venation is obscurely traceable also in D. ruscifolia , and the 
cells are much smaller than are those of D. Hypoglossum. 
There is also a marked difference in the shape of the cysto- 
carp, which in D. Hypoglossum is somewhat flattened, but in 
D. ruscifolia has an elongated neck, and a carpostome with 
everted rim. As in D. Hypoglossum , each branch of the female 
plant usually bears a cystocarp, though occasionally, as in 
Harvey’s figure (’51), two may occur on the same midrib. 
The procarps occur on the midrib only, but the arrangement 
is by no means so regular as in the three preceding species. 
Occasionally no procarp will occur on an axial cell, or two 
successive joint-cells bear procarps inclined towards the same 
side, or a procarp will occur on one surface but not at the 
corresponding situation on the opposite surface. A more 
important deviation is the rare occurrence of two carpogonial 
branches arising, one on the right, the other on the left of 
the same pericentral cell. The cells of the carpogonial branch 
are also more uniform in this species, though in this respect 
it resembles D. Hypoglossum. 
The condition of the young cystocarp figured in Fig. 20 
may often be found. It is probable that it represents a pause 
in the sequence of events between the fertilization of the 
trichogyne and the production of the gonimoblast-filaments. 
If so, this lends additional support to the idea that the 
anterior cell cut off from the pericentral cell is the auxiliary 
cell, as the halt may be accounted for by the fact that at this 
stage the conjugation of the carpogonium with the auxiliary 
cell would occur. As in the other species, it is from this 
anterior cell alone that the gonimoblast-filaments arise. 
