on 
SI 
=D | 
(1855, p. 43, figs. 8—9), later by BurFHAM 
(1893, p. 294, pl. XIII, figs. 13—14), and 
more recently E. M. DErr and V. M. Gruss 
have given an account of their development 
(1924). According to the latter authors, the 
development of the male sori begins with a 
transverse division of the superficial cells. The 
lower cell thus formed is the basal cell, the 
upper one the antheridial mother-cell, which 
can produce in alternate succession at least 
four antheridia. Male specimens were met with 
in March and April. 
Female sex organs and cystocarps are 
quite unknown; and as they have certainly 
been searched for repeatedly by many algolo- 
gists in this wide-spread alga, it seems prob- 
able that they are really wanting. As mentioned 
above (p. 573), the interpretation of the hyaline 
hairs as trichogynes cannot be maintained. 
When the carpogonia are wanting, the question 
of the occurrence of a reduction division in 
the developing tetrasporangium will be of great 
interest. In case the reduction division can be 
definitely ascertained, a mixie might be supposed 
to take place at one or other moment of the 
life-history of the species. If a regular meiosis 
does not take place, there will be good accord- 
ance with the fact that a normal fertilization 
does not occur. In any case the spermatia are 
functionless though their structure is apparently 
quite normal. According to the facts known 
it must most likely be assumed that the reduc- 
tion division in the tetrasporangia is initiated 
but not fulfilled owing to the wanting process of 
fertilization. 
Rhodymenia palmata grows on stones and 
on various Algæ, most frequently on the stipes 
of Laminaria digitata and hyperborea, further 
on Fucus serratus, Furcellaria fastigata, Chondrus 
Fig. 571. 
Rhodymenia palmata. From the Baltic, QZ off 
Moens Fyr, 7.5 m, July 1894, ?/, nat. size. 
crispus, Phyllophora membranifolia and on roots of Zostera. It occurs most frequently 
at depths of (5), 7—20 m, more rarely down to 24 m. At slighter depths, 
1 m, it has only been met with in harbours (Frederikshavn, Lille Belt). It grows 
