178 Phillips . — The Development of the Cystocarp 
cell. By appropriate means, the much longer, somewhat 
attenuated axial cell may be seen lying below these cells, and 
it may be traced, even in the vegetative thallus, in an un- 
divided condition for great distances behind the situation 
described by Wille. In the young proliferations in which 
the cystocarps arise, there is no difficulty in tracing the 
undivided cells of the axial row from base to apex. 
I now proceed to describe the structure and arrangement of 
the procarps in these phylloid branches. For some few cells 
behind the apical cell, the axial cells, while they give off 
laterally pericentral cells, which grow out to form the lamellar 
wing, right and left of the mid-line, do not cut off cells 
parallel to the flat surface of the thallus. This, however, 
soon occurs, and immediately following upon the appearance 
of these pericentral cells above and below, is the appearance 
of the carpogonial branch. The pericentral cell cuts off, 
obliquely, right or left posteriorly, a cell, which is the first 
cell of a 4-celled carpogonial branch. The branch curves 
round right or left of the pericentral in a plane roughly 
parallel to the surface, and in such a way that the carpo- 
gonium itself is brought forward to a level with the apical 
part of the pericentral cell which bears the branch, and the 
trichogyne there passes out obliquely to the surface. The 
trichogyne is inflated at the extremity, and extends but little 
beyond the surface. Of the four cells of the carpogonial 
branch, the first two are each larger than the third and 
fourth, and the second is considerably larger than the first. 
As this cell takes up Hoffmann’s blue readily, the position of 
the carpogonial branch can easily be determined even with 
a low power by its means. The third and fourth cells are 
small, and are with difficulty distinguishable from one another 
for some time after the cell-division which gives rise to the 
carpogonium. 
Such a carpogonial branch is borne by the vertically 
situate pericentral cell of every joint along a considerable 
length of the fertile branch. They lean however to the right 
or left of the mid-line in regular alternation. Further, when 
