513 
B. Jönsson (1891, p. 19); Schmitz, Actinococcus (1893), p. 367; Darbishire (1895) pp. 5, 10, 20, 27, 
31, 34; Kylin, Entwick. Florideenstud. (1928) p. 54, fig. 33. 
Fucus membranifolius Good. et Woodw., Trans. Lin. Soc. III (1797), p. 120, pl. 16, 
fig. 1, 2. 
5 
Fucus crispatus Fl. Dan. tab. 826, fig. 1 (1778). 
Fucus rubens Fl. Dan. tab. 827, fig. 1 (1778). 
Spherococcus membranifolius C. Agardh Sy 
nops. Alg. scand. (1817), p. 26; Lyngbye Tent., p. 10, tab. 3C. 
Spherococcus Palmetta Lyngbye 1819, p. 11 ex parte. 
Phyllotylus membranifolius Kützing, 
(1869) Taf. 75 (c. nemathec.). 
Phyc. gener. (1843) p. 412, Taf. 62 I (cystoc.), Tab. phyc. XIX 
The shoots arise in various number from an expanded basal disc, of a similar 
structure to that in Ph. Brodici (comp. DARBISHIRE |]. c.). It has a very thick outer 
wall and is built up of densely 
united vertical rows of cells that are 
square or higher or lower than broad; 
the uppermost cells are usually low. 
The cells contain numerous grains 
of floridean starch that are stained 
blue by iodine. The outermost cells, 
however, contain no starch grains 
but similar refractive bodies that 
do not stain with iodine. They give 
no reaction with osmic acid, and 
take a feeble red colour with hæma- 
A 
B 
Fig. 477. 
Phyllophora membranifolia. Small specimens with short stipe 
Sallingsund, Limfjorden. July. Photo, nat. size. 
toxylin (Hansen), while the starch grains remain quite colourless. By treatment 
Fig. 478. 
Phyllophora membranifolia. Groves 
eastern Kattegat, April. Photo, */, 
Flak, 
n.s. 
D.K. D. Vidensk. Selsk. Skr., 7. Række, naturvidensk. og mathem. Afd., VII, 4. 
with caustic potash they swell somewhat and 
become less refractive; by the following washing 
out in water and treatment with iodine they stain 
feebly yellow; they give no reaction with bichro- 
mate of potassium nor with nitric acid and with 
ammonia after treatment with nitric acid. Their 
chemical quality thus remains unknown. 
The young shoots that may be met with 
in summer on the vertical faces of boulders 
and which have arisen after the last winter, 
have often a very short terete stipe while the flat 
part of the frond is broad and repeatedly bifur- 
cate, and this is especially so in the first erect 
shoot of young plants; a lateral shoot then 
often arises from the short stipe (fig. 477 A). In 
other cases the stipe is long, in particular in 
older plants, where it may be 4—5 cm or longer. 
At the end of the first period of vegetation the 
frond has thus the shape of a well deyeloped fan 
66 
