1916 
Fig. 499. 
Phyllophora Brodiei. Frond col- 
lected in June 1922 east of Heste- 
skoen NE of Als at 18—19 metres’ 
depth. The oldest part of the 
frond has probably arisen in 
?/, nat. size. 
1916. 
524 
7 generations of shoots could 
be ascertained, undoubtedly re- 
presenting an equal number of 
years. The specimens growing here 
attached to stones attained a length 
of 33 cm but had a very narrow 
frond, undivided orscarcely divided 
by dichotomy. 
A particular kind of shoots 
are the folioles, flat or nearly 
Fig. 500. 
terete small shoots which arise Phyllophora Brodiæi Transverse 
at the upper margin of the leafy section of the stem near the hold- 
> à 
fast. 
frond and which usually produce Fra 
the sex organs (fig. 502). These shoots, however, are not 
always fertile, and in a loose form (f. stellata) similar shoots 
but sterile and often branched give to this form a charac- 
teristic habit (figs. 517 D, 518). 
The anatomical structure will not be mentioned here, 
as it has been treated by WırrE (1887) and DARBISHIRE 
(1895). A transverse section of the stem of an older frond 
near the attachment disc is shown in fig. 500. There are a 
number of concentric cortical layers, partly incomplete, 
the limits between them often vanishing or merging. 
The central tissue has an elliptical out- 
line. As shown by DARBISHIRE (1895, 
p- 20, fig. 25,1), secondary cortical layers 
(sekundäre Verdickungsschichten) may 
also be produced at the base of branches, 
but they may further arise sometimes as 
local formations in the sexual shoots, 
as I, too, have observed. According to () 
DARBISHIRE, the young cells contain a single 
chromatophore. In the large cells in the inte- 
rior of the frond several long ribbon-shaped 
chromatophores can be distinguished. 
According to H. CLAUSSEN the vegeta- Fig: 501. | 
tive cells contain several small nuclei (1929, anal, 
p- 546); the smaller cells of the cortex seem, Jar tissue of leafy 
however, to contain a single nucleus. frond QUES 
The reproduction of Phyllophora Brodiæi has been 
much disputed for more than a century. TURNER, who 
described the species in 1809, interpreted the globular bodies . 
