299 
This species of Dittwyn is the first described plant of this form series. It must 
be granted that the description only comprises sterile plants, but there is no doubt 
Fig. 202. Fig. 203. Fig. 204. 
Spermolhamnion repens. Filament showing the nuclei and the formation Spermothamnion Spermothamnion 
of the branches. repens. Upper end repens. Two-celled 
of thin filament. hapter. 158:1. 
300 : 1. 
that it refers to incompletely developed specimens of €. Turneri. Its occurrence on Fur- 
cellaria fastigiata which is a favourite substratum of S. Turneri speaks decidedly in 
favour of it. It must therefore be most correct to give the plant Dirzwyw's specific 
name which is 4 years earlier than that of MERTENS. 
The Danish specimens may be referred to two IP 
forms: f. Turneri and f. roseola, which are shortly À 
characterized above. The first-named form has only 2 
been found in the North Sea, the Skagerak and the VL 
northern Kattegat, while in the specimens from the 
inner Danish waters the branches are rarely or never 
opposite and the sporangia are placed singly or in 
pairs on short pedicels. No distinct line of demar- 
cation between the two forms can however be drawn, 
the characters varying considerably even on the 
same plant. 
As shown by NÄGELT (l. c. p. 346), there is a 
distinct morphological difference between the hori- 
zontal filaments, which constanily grow in a trans- 
versal direction, and the erect filaments given off N 7 
from their upper side. New creeping filaments are a 
given off from the flanks of the first named filaments \ | 
while rhizoids are produced from the under face. \\ 
The cells contain numerous nuclei, not only N 
the older cells but also the apical ones which con- || 
tain a considerable number in thicker filaments. 
. . . ie. 205 
They appear in the apical cells as hyaline globular _ RE, 
3 = > : = à Spermothamnion repens. Normal and ter- 
bodies dispersed in the peripheral part of the dense minal hapters. 50:1. 
