Fig. 402. 
Brongniartella byssoides. Store Belt, May. Procumbent 
shoot giving off an erect shoot. The upper figure is the 
continuation of the lower, but eight joints without tricho- 
blasts have been omitted; the lowermost joint in the 
upper figure is the 17th from the base. 50:1. 
unbranched trichoblasts also occur, f. inst. 
on the lower part of the erect shoots 
(fig. 402). The cells of the full-grown 
trichoblasts contain a number of nuclei. 
The long shoots have 7 pericentral 
cells but in the shoots of higher order 
the number is frequently only 6 or even 
5, and in the creeping shoots, too, only 
5 or 6 pericentral cells were found. Cor- 
tication is wanting. 
In the long erect shoots an axillary 
shoot is usually given off from the basal 
cell of all the trichoblasts; the lowermost 
trichoblasts, however, are often not ac- 
companied by axillary shoots, and the 
same may sometimes be the case with 
single trichoblasts among the usual ones. 
The first joint of the axillary shoot, 
common to this and the trichoblast, has 
usually 4 pericentral cells, as stated by 
FALKENBERG (1901 p.545), but the number 
may be smaller, e. g. 2, as described by 
Kny (1873, p. 106, comp. our fig. 404, 
405 A). The normal axillary shoots arise 
comparatively late, on the kathodic side 
of the basal cell, according to FALKEN- 
BERG at the 20th to the 30th segment of the mother shoot; they may, however, 
arise earlier, e. g. at the 8th to the 10th joint. The pericentral cells of the basal 
joint are cut off shortly after the form- 
ation of the axillary branch. The direction 
of these cells is usually very different from 
that of the pericentral cells of the follow- 
ing joints, coinciding with the direction 
of the trichoblast, while the direction of 
the axillary branch diverges almost at right 
angles from the trichoblast (fig. 405). As 
shown by FALKENBERG, it happens that no 
axillary shoots are produced in feebler 
branches, but notwithstanding that four 
pericentral cells are cut off from the basal 
cells of the trichoblasts. The same has 
been found by me in Polysiphonia nigrescens 
Fig. 403. 
Brongniartella byssoides. A, transverse section of stem. 
B and C, transverse sections of tetrasporiferous branch. 
B, fertile joint after evacuation; C, sterile joint of tetra- 
sporiferous branch. 200 : 1. 
