180 Phillips . — The Development of the Cystocarp 
vegetative leaf-like shoots when fertilization fails. They 
resume the vigorous apical growth, and, ceasing to give rise 
to procarps, attain great lengths. This I infer from the fact 
that in young branches which are considerably longer than 
those in the receptive stage, I could still distinguish the 
remains of procarps in the basal region. Vegetative shoots 
certainly arise here and there in the fringe of fertile shoots. 
Such a reversion cannot, however, occur on a large scale ; for 
the young procarp-bearing proliferations may be counted by 
scores, while the number of vegetative branches on a plant 
hardly reaches a dozen. 
The first indication of the appearance of a cystocarp in 
these fertile branches is best afforded by staining. One cell 
of the axial row, the four pericentral cells connected with it, 
and the adjacent axial cells before and behind, seven cells in 
all, become so deeply stained by Hoffmann’s blue, that this 
region can then be readily distinguished with the aid of even 
a hand-lens. I have always found that this stain is taken up 
with greatest avidity by those cells in which there is great 
metabolic activity, or a relatively large quantity of proto- 
plasm. Thus, the apical cell, the cells of the carpogonial 
branch, the auxiliary cell, and carpospores and tetraspores in 
Florideae, all stain deeply. In the ordinary vegetative cells, 
it is only the chromatophores and the nucleus that stain 
readily, the ordinary cytoplasm being hardly tinged in 
glycerine-material. The deep staining of the cells referred 
to above indicates that one of the procarps connected with 
the axial cell, which is the centre of the group, has in all 
probability become fertilized, and that physiological changes 
ensue in neighbouring cells, analogous to those which occur in 
an ovary when the seeds are fertilized. When this stage is 
reached, however, it may be inferred that a considerable time 
has already elapsed since the attachment of the spermatium 
to the trichogyne. In the cases examined, the trichogyne 
was already so much immersed and obliterated, that it was 
useless to look for evidence of the presence of the spermatium. 
Such deeply stained groups of cells show also a consider- 
