179 
fertilization '. Sporogenous filaments are found given off not only from the carpo- 
gonium but also from other cells in the carpogonial branch; in the latter case, 
however, fusion between these cells and the carpogonium could not always be dis- 
cerned, as for instance in fig. 98 E, where two young sporogenous filaments are 
seen projecting from the carpogonium and the subjacent cell. Older stages are 
shown in fig. 99 C and E; in C the filaments causing the fusion ‘between the cells 
of the carpogonial branch are 
easily visible. The sporogenous 
filaments are here seen growing 
out in a horizontal direction from 
the carpogonial branches. Fig. 
98 I, K show auxiliary cells in 
contact with sporogenous fila- 
ments, and fig. 99 G represents 
probably the same after the fusion. 
The stages shown in figs. 99 D 
and 98 L are probably young go- 
nimoblasts, though sporogenous 
filaments are not visible. Ripe 
cystocarps are shown in figs. 99 
H, I; they consist, as shown by 
Batters (1. c. pl. XI, fig. 4), of an 
almost spindie-shaped heap of 
carpospores which easily segre- 
gate on preparation. The spores 
are 14 to 17 » in diameter. 
The species has been found 
in almost all the Danish waters, 
in depths of 1 to 19 meters. It Fig. 99. 
grows on stones and shells of  Petrocelis Hennedyr. A, two-celled carpogonial branch, January. 
0 5 o 9 6 B-D, Begtrup Vig, May. B, three-celled carpogonial branch, un- 
Mytilus edulis and Littorina littorea, fertilized. C, carpogonial branch after fertilization (?), giving off 
en conpany with CE eS ee ee 
Lithothamnia and growing over nous filaments (Skagerak, April). F-G, Hellebæk, July. F, carpo- 
om, m ee ee 
gerak it has principally been found fully developed, Lysegrund, May. I,ripecystocarp, Storebelt, January. 
growing on the stem of Laminaria er ERE 
hyperborea. The sporangia begin their development as a rule in the autumn; 
they were found undivided in September and November, ripe in January to July, 
emptied or abortive in June to September and November. But young sporangia 
G 
1 Spermatia have not been found adhering to the trichogynes, and in some cases carpogonia having 
produced sporogenous filaments show no interruption of the protoplasm over the ventral part (fig. 98 E, 
99 E) which might suggest a parthenogenetic development of the cystocarp. 
23* 
