260 
W. J. Hodgetts. 
III.—On the Occurrence of “False-branching” in the 
Hormidium- state of Prasiola crispa. 
As is well-known, the cells of the common filamentous form, 
or Hormidium- state, of Prasiola crispa frequently divide by 
longitudinal as well as transverse walls to form two or more rows 
of cells {Schizogonium- state), which by further divisions produce 
flat expansions of cells (Prasiola- state). True branching in the 
Hormidium-state, of this Alga appears to have been recorded only 
in connection with the production of rhizoids. Wille, for example 
has described a submarine form of Prasiola crispa (termed f. 
submarina 1 ) in which certain cells of the filaments had grown out 
to produce short unicellular rhizoids; only very occasionally did 
these rhizoidal branches consist of several cells. 
Choldat 2 mentions and figures uni- and multi-cellular, simple 
and also branched, rhizoids in Schizogonium crispum (=Prasiola 
crispa). Heering, 3 speaking of the rhizoids of Prasiola says: 
“ Selton werden diese Ausstiilpungen durch eine Scheidewand von 
der Mutterzelle abgegrenzt und wachsen zu mehrzelligen Faden 
aus.” 
The writer, however, found pseudo-branching of a character 
quite different from rhizoid-production in a patch of the Hormidium- 
state of Prasiola crispa which occurred on damp ground under a 
tree in a field at Warley, near Birmingham (in April, 1919). As 
will be seen from the description below, this pseudo-branching is 
exactly similar as regards mode of development to the false- 
branching in the Blue-green algal genera Tolypothrix and 
Scytonema. 
The mode of development of these pseudo-branches, which 
were quite frequent and not merely of isolated occurrence in 
specimens of the Alga from the locality mentioned, is illustrated in 
Fig. 2, A-D. At intervals along most of the filaments there were 
short lengths o$4 to 3 (rarely more) dead, apparently empty, and 
generally much flattened cells (Fig. 2, A). 
The living cells on one or both sides of these dead cells, by active 
division and growth had, in the case of many filaments, pushed 
their way out through the hyaline sheath surrounding the filament 
(Fig. 2, B, C.) as short lateral pseudo-branches (Fig. 2, D). 
1 Wille, N., Studien iiber Chlorophyceen, III, Vid.-Selsk. Skrifter. I. 
Math.-naturv. Klasse, 1900 (Christiania), pp. 13-18, Taf. 1, Figs. 42-53. 
3 Algues Vertes de la Suisse, Berne, 1902, p. 342, and Fig. 251. 
3 Heering, W., Die Siisswasserflora Deutschlands, Heft. VI, 1914 (Jena), 
p. 56. 
