340 
between cells which were before-hand connected by a pit. The process is not ac- 
companied by a migration of nuclei; the two cells fusing with each other contain 
each one central nucleus like the other cells. 
The sporangia are borne on the inner side of the branches of the last or penul- 
timate order. They are 4-parted or 2-parted, most frequently the first, but there is 
always one sort of sporangia only on 
the same plant. They form a short row 
on the inner side of the branches, fre- 
quently in a number of 3 or 4, but 
sometimes there is only one, on the 
first joint. When the number is greater, 
they are not always all placed on the 
inner side~but some of them on the 
flanks of the branches (fig. 265). There 
is usually one sporangium only on each 
joint but a young sporangium may 
sometimes be found under the normal 
one, more rarely over it. Such small, 
incompletely developed sporangia were 
met with in plants with four-parted and 
with two-parted sporangia as well, most 
frequently in the latter. The sporangia- 
bearing branches may be simple but 
are frequently branched and the bran- 
ches then issue over the sporangia- 
bearing part (fig. 266). It is very rare 
to find a cell bearing at the same time 
a sporangium and a branch (fig. 273). 
The sporangia are ovate or obovate 
or broadly ellipsoid. The tetrasporangia 
are tetrahedrically divided, but the spores 
are sometimes so arranged that the spo- 
i 5 _ Fig. 266 a i rangia seem to have been cruciately 
Callithamnion Furcellariæ. Part of plant with disporangia. We 3 
From YV. 200 : 1. divided (fig. 265), a fact to which Hauck 
has already paid attention in the species 
mentioned by him under the name of C. byssoides (Österr. bot. Zeitschr. 1878 p. 288, 
Taf. 3 Fig. 9). The tetrasporangia are (44—) 53—79 w long, 33—51 w broad. When 
the specimens from the waters within Skagen only are taken into account, the size 
is a little smaller, viz. (44—) 53—65 (—67) u long, 33—42 w broad, which quite agrees 
with the dimensions stated by Kyrın. The specimens from the Skagerak, some of which 
were not with certainty referable to this species, had larger sporangia, 66—79 w 
long, (38—) 42—53 u broad. 
