423 
Polysiphonia violacea €, lenuissima Aresch. 1. c. p. 54, Hauck, Meeresalg. p. 227. 
Polysiphonia roseola Kützing Tab. phyc. Bd. 13 Taf. 80. 
0, aculeata (Ag.) 
Hutchinsia aculeala Agardh Synopsis Alg. Scand. p. 59. 
Polysiphonia aculeata J. Agardh, 1863 p. 947, Kützing Tab. phye. Bd. 13 Taf. 71. 
Polysiphonia aculeifera Kützing Tab. phyc. Bd. 13 Taf. 71. 
Hutchinsia implicala Lyngbye Hydr. p. 111, Flor. Dan. tab. 1955. 
Hutchinsia divaricata Ag. Syn. Alg. Scand. 1817 p. 59. 
Polysiphonia divaricata Kützing Sp. Alg. p. 822, J. Agardh, 1863, p. 947. 
Polysiphonia violacea is here taken in a larger sense than by earlier authors, 
not only P. aculeata (Ag.) but also P. fibrillosa (Dillw.) being included in it, while 
the latter has hitherto been regarded as a distinct 
species. 
The morphology and development has been 
described by Kny (1873, p. 104, P. fibrillosa), my- 
self (1884) and FALKENBERG (1901). The primary 
axis is usually very distinct; in the f. {enuis only 
it is very thin and not easily discernible from the 
longer branches. The basal disc is composed of 
numerous densely crowded rhizoids terminating in 
attachment discs (fig. 365, comp. L. Batten 1923 
figs. 55, 59). According to FALKENBERG (1901, p. 
116) adventitious, partly creeping branches are later 
given off from the base of the plant. This may be 
so, as I have convinced myself, but usually such 
adventitious shoots are not produced (comp. Harvey 
Phyc. Brit. Plates 209 and 302). In some cases, how- 
ever, I found a great number of small adventitious 
shoots arising from the basal disc, being first creep- 
ing and then ascending and producing erect branch- 
es, and I also found erect shoots issuing directly 
from the basal disc. Such adventitious shoots are 
perhaps more common in f. fenuis. 
The trichoblasts are arranged in a regular 
spiral, with a divergence varying between !/, and 
I, of the circumference. Each joint of the shoots 
bears a trichoblast with the exception of the lower- 
most joints of the primary axis and of the branch- 
es. The first trichoblast on the branches is most 
Fig. 365. 
0 Ss ES Polysiphonia violacea. A, young plant grow- 
frequentiy placed on the third joint, the basal joint ing on Polysiphonia elongata, June 15th; 
included, more rarely on the 4th, very rarely on a procarp is developing in the trichoblast 
on the 20th joint. B, base of a hardly one 
the second joint; in a specimen collected at Gjelle- em high plant. 100 :1. 
54* 
