573 
spots, where each superficial cell may bear a hair, while no hairs are found out- 
side these spots (fig. 569, comp. L. K. R. 1911, p. 212). They are easily visible in the 
living plants, and the spots can be 
distinguished in dried specimens (fig. 
567). The hairs were met with in the | 
months of March to July; they are Li 
then shed, and the plants are hairless \ ze 
from August to the end of the winter. “ y \ AP 
The hairs were first described by WILLE VA "Ari, EN 
(1891, p. 103). V. M. Gruss took them S 
Fig. 569. 
for trichogynes (1922, P- 151), a view Rhodymenia palmata. A, transverse section through a part 
which cannot be maintained, as true of a spot of hairs (400 : 1), B, base of a hair (630 : 1). (From 
procarps have never been ascertained, 
and as the hairs occur on tetraspore-bearing and on male individuals, while female 
specimens are unknown; the hairs are purely vegetative organs agreeing with the 
hyaline hairs of such common occurrence among the Florideæ. 
The large medullary cells do not contain starch as storage matter. On the 
other hand the frond contains a soluble carbohydrate which, according to Kyrın 
Fig. 570. 
Rhodymenia palmata. 
Stipe of young plant. 
The large cells of the 
medullar tissue are to 
be seen in the upper 
part of the stipe. About 
50 : 1. 
K. Rosenvinge 1911, p. 212). 
(Zeitschr. physiol. Chemie 101 1918, p. 245), is trehalose and may 
amount to 14.8 p.c. of the dry weight.! 
Kırrıan has followed the development of the germinating 
spores, without doubt tetraspores, which he found on stipes of 
Laminarie. The spore is divided by vertical and horizontal divi- 
sions, forming an hemispherical attachment organ, at the top 
of which a cell becomes larger than the others and takes the 
function of the initial cell of the young frond, which is at first 
fusiform, later flattened. The apical initial cell only functions 
in the quite young frond; it is early replaced by a multicellular 
meristeme, but its existence is of great interest, suggesting, as 
emphasized by Kırrıan, that Rhodymenia palmata may be derived 
from the type with a central axis (“Centralfadentypus”). 
The upper portion of the stipe contains a medullar tissue 
gradually tapering downwards. In a cross section it appears as 
an oblong or elliptical group of large cells sharply bounded towards 
the thick cortical tissue composed of radiating cell-rows. This 
cortex shows stratification in older fronds (comp. Jonsson 1891, 
p. 23, KırLıan 1926, p. 207). In a specimen from Skagen, which 
was judged to be two or three years old, the presence of two or three layers in the 
cortex was ascertained. 
7 According to a recent note by H. Corın and É. GUÉGUEN the sweet principle of this Alga 
is a monogalactose of glycerol. (Acad. d. sciences, Paris, July 21, 1930; cited from Nature, No. 3176, 
Vol. 126). 
