147 
Helminthocladia J. Agardh. 
1. Helminthocladia purpurea (Harv.) J. Ag. 
J. Agardh, Spec. II, p. 414, III, p. 506; Flora Danica tab. 2699; Schmitz, Chromatophoren der Algen, p. 63 
fig. 11—12. 
Mesogloia purpurea Harvey in Hooker Brit. Flora II, 1833, p. 386. 
Nemalion purpureum Chauv.; Harvey, Phye. Brit. PI. 161; Kützing, Tab. phyc. 16. Band Pl. 62 c, d. 
The structure of the frond is somewhat similar to that of Nemalion mullifidum, 
but the assimilative filaments are composed of larger cells, of which the terminal 
ones are the largest (fig.71). These terminal 
cells bear no hairs, and these organs are 
upon the whole rare in the older parts of a Hh 
the plants, while they occur fairly abun- 
dantly in the younger parts. They are 
given off from thinner branches not reach- 
ing the surface of the frond and are partly 
terminal, partly lateral; they have the same 
structure as other similar hairs, are fairly 
thick and attain a considerable length (fig. 
71 A, B). Besides the hair a little cell with : à | | 
fairly dense contents is visible; such cells SD 107 
are also to be found in the older parts of | EN Z 
the frond without hairs. The chromato- 
phores which are particularly large and 
well developed in the terminal club-shaped 
cells, contain as shown by Scumirz (l.c.) a 
large central pyrenoid which in some cases 
was readily visible as a dense body, while 
in other cases they conveyed rather the 
impression of being vacuolar cavities like Fig-571. 
those stated for Nemalion by Worre (figs. minthetadic purpurea, À end el asimiative fhe 
71 A, 72 A, B). C, young ‘celled carpogenic filament. D; assimilative 
The antheridia form dense, often hemi- Tu hen nal na Dach en er 
spherical clusters at the end of the assimila- ?celled earpogenie filament. F, carpogenie branch 
tive filaments. The outermost cells are then ot Sa DVD alin D 
small and bear a number of short much branched antheridia-bearing branchlets. 
These branchlets are shorter than in Nemalion and Helminthora and their joints 
are often nearly globular (fig.72 A—C). In some cases a number of globular cells 
were found crowded together at the upper end of the last cells in the assimilative 
filaments (fig. 72 E, F). These cells, which were larger than the antheridia and 
contained a thin chromatophore, might be suggestive of monosporangia; they were 
however certainly no such organs but probably only checked antheridial branches, 
19° 
