374 Fritsch, Observations on the young plants of Stigeoclonium Kütz. 
baren Aufquellen der Wände und zuletzt zu einer unveränderten 
Zellwand.“ Palmelloid groups which probably belonged to the same 
form were also observed ın the same water, but their cells were 
not found in connection with young plants of Stigeoclonium. This. 
would agree with Cienkowski’s observation that ‚je weniger das 
Stigeoclomum in der Auflösung seiner Glieder vorgeschritten ist, 
desto leichter treiben seine Zellen Schläuche, dagegen an der äusser- 
sten Grenze der Umformung angelangt, im vergallerteten Zustande, 
verlieren sie in den allermeisten Fällen diese Eigenschaft“. (loc. 
eit p. 549). Famintzin (71, p. 265) had shown that the proto- 
coccoid cells, derived from Stigeoclonium, were capable of immediate 
germination; whereas Cienkowski showed that the palmelloid cells 
usually gave rise to microgonidia and these then to the young 
plant. 
Gay (loc. cit. Fig. 57) figures young plants of Stig. nanum, 
which possess a creeping basal portion, whose cells are considerably 
more swollen than those of the upright branches. His Fig. 58 shows 
the base in surface view; the cells then appear rounded-polygonal 
in outline and have thick membranes. The same observer also figures 
the young plants of Stig. variabile (Figs. 48—50); these have a 
basal creeping portion (‚rhizome germinatif‘), in which again the cells, 
relative to those of the upright part of the plant, are much dis- 
tended. This scarcely concurs with my observations, which is pro- 
bably due to our in reality examining different species. 
I have already twice referred to the fact, that especially in St. 
variabile the young: plants often exhibited no creeping portion what- 
ever (cp. Tab. XI, figs. 15 and 18). In such upright filaments the 
basal cell is generally specially modified (Fig. 15), although it is 
often so densely surrounded by a mass of brownish-red matter!), 
that this point is not easy of observation (cp. Figs. 13, 18). A 
single upright filament with a modified attaching-cell basally was 
also sometimes observed in Si. farctum (Figs. 12, 13), although the 
usual type of young plant is here entirely different. The modified 
basal cell is not at all unlike that found in some species of Oedo- 
gonium, although relatively much smaller. Kützing (53) figures 
such basal cells in a number of species of Sigeoclonium; on Tab. 4, 
fig. Ild for St. stellare;, on Tab. 7, fig. II for S1. radıans Kütz.; 
on Tab. 8, fig. I for St. fascieulare Kütz. and fig. II for St. 
protensum Kütz. However neither Berthold (78) nor Gay (91) 
figure anything of the kind. 
The basal cell, being thus especially modified, and having more- 
over often lost its contents (see. fig. 15) there seems little proba- 
bility of its later on growing out to form a horizontal base; at all 
1) This brownish-red matter has already been referred to in the case of 
Oedogonium (Fritsch 02B, p.473) and it was tbere shown to consist of some 
salt of iron with the help of the characteristic Prussian blue reaction. Be- 
sides occurring to some extent near the points of attachment of young plants 
of Stigeocionium, 1 have also observed it in many other places, — notably 
at the points of attachment of Synedra splendens and Characium Sieboldi to 
other filamentous Algae. It would thus seem as though this substance played 
an important part in the adhesion of one Alga to another, possibly acting as 
a kind of cement. “ 
