173 
KÜTzınG, Caspary, THURET (1878, p. 75, pl. 37, fig. 6) and Denys. The outer cortex 
consists of a greater number of layers of small cells (up to 4 or 5) than in Furcel- 
laria. The longitudinal filaments of the central tissue are mostly thicker at the ends 
than in the middle “so that they have the form of a femur” (Caspary, p. 94). The 
cells which form the connection between these filaments and the cortical ones are 
arranged in regular feebly curved rows running obliquely upwards, while secondary 
hyphæ are wanting’. Hyaline hairs produced by superficial cortical cells may 
occur, according to THURET (1878, p. 75, pl. 37, fig. 6). I have not observed these 
hairs, but in specimens collected in April I found that some of the peripheral cells 
were colourless, narrower and longer than the others; probably they were about to 
develop into such hairs. As to the cell-structure, reference may be made to the 
paper of Denys. The pit in the transverse wall between the cortical cells is very 
narrow, while that of the longitudinal filaments is broad, and provided with a 
double plate. Secondary pits do not occur. The structure of the basal disc has 
been figured by Ktrzine (1843); according to Korkwirz (1900, p. 51) older dises are 
stratified. 
The tetrasporangia arise at about the limit between the outer and inner cortex 
(comp. Caspary, 1850, fig. 21, THURET, 1878, pl. 36, fig. 6 and 7). As shown by THURET, 
an issue is formed outwards to each sporangium by removal of the cells from each 
other, through which issue the contents of the sporangium is emptied. Specimens 
with undivided sporangia have been met with in October, with ripe sporangia in 
January and with emptied sporangia in April. 
The antheridia arise, as shown by THURET, in nemathecia in particular indi- 
viduals. According to GUIGNARD (1889, p. 44, pl. 6, fig. 10—12) they are placed in 
tetrads directly on the nemathecial filaments, while Schmitz asserts (1893, p. 8) that 
they are situated on short cells given off from the filaments. I cannot give any 
information on this point, as I have not met with male plants in the Danish waters. 
As to the structure and development of the female nemathecia, reference may 
be made to the classical researches of THURET and Bornet (1878, p. 77—80, pl. 38—39). 
These bodies begin to develop in the Danish waters in August or September. In 
specimens dredged at the entrance to Vejle Fjord, August 20th, nemathecia with 
well developed but unfertilized carpogonia were found. Similar carpogonia but also 
others with fertilized carpogonia are frequently met with in September. Ripe cy- 
stocarpia were found in December and January. After the exhaustion of the carpo- 
spores, the nemathecia are thrown off, while the fronds which have produced them 
possibly may continue growing. — The germination of the carpospores has been 
observed by THURET et BORNET (1878, p. 79, pl. 39, fig. 32); they obtained hemi- 
spherical bodies producing rhizoids from their under face. 
1 Denys speaks (1. c. p. 7) of “Querhyphen, welche die Masse der längs verlaufenden durchflechten 
und seltener auch zwischen die Elemente der grosszelligen Rinde eindringen”. But as he designates 
the longitudinal filaments also as “‘Hyphen”. it is not clear if it is a case of real hyphæ or only of the 
above named connecting filaments. As he says, on p. 18, that they occur only “ganz vereinzelt”, it 
seems that he has really observed secondary hyphæ, although in very small number. 
