Fig. 147. 
Lithothamnion polymorphum. Vertical section 
of emptied sporangial conceptacle, showing two 
muciferous canals and the covering tissue. 
About 350:1. 
a 
ceptacle. The newly evacuated conceptacles are 
sometimes covered by a peculiar, rather thick 
tissue, which is sharply marked off from the roof 
(fig. 146 E, 147, Plate III fig. 6). Its cells are fre- 
quently broader than tbose of the roof, (fig. 147). 
In a living state this covering tissue appears as a 
white dot. It has been mentioned by FosLie (Re- 
marks, p.78). A similar tissue also occurs overthe 
sexual conceptacles. Its signification is unknown. 
Antheridial conceptacles I have not seen; 
they have been mentioned by HEyDrıcH (1900, p. 
68, Taf. II fig. 1—3) and Foslie (1905). According 
to the first named author, the spermatia are 
produced from branched filaments given off 
from the inner side of the conceptacle, as it 
seems, in a similar manner as in L. Lenormandi. 
THURET states (Et. phyc., 1878, p. 91) that the spermatia resemble those of Jania rubens. 
The cystocarpic conceptacles are, according to FOSLIE, at first convex, but they 
are not always so, for fairly young, totallv immersed conceptacles may be found 
(fig. 148). As to the development of the cystocarp more detailed statements are given 
by HEypricx (1. c. p. 70) which are in several respects in discordance with those of 
Sots for other Corallinaceæ. They very much need a critical trial, but as I have 
had only dried specimens 
at my disposal I can only 
throw little light upon the 
matter. Before fertilization 
the concave bottom of the 
conceptacle is covered with 
numerous procarps which 
aretwo-celled, asshown by 
Heypricu (fig. 148, Plate III 
fig. 5). These filaments are 
intensely coloured by hæm- 
atoxyline. The lowest cell 
is probably an auxiliary 
cell, as maintained by 
Heypricu, and this is also 
in accordance with the 
statements of MINDER for 
Choreonema (Fruchtentw., 
p. 12). This cell may be 
rather long (fig. 148 C). The 
C= 
Lithothamnion polymorphum. 
carpogonia. B, similar, with a rather long neck. C, procarps. 
section of the bottom of a female conceptacle, showing fusions between the 
) 
Ÿ | I, 
) Af. BR 
Fig, 148. 
4, verlical section of female conceptacle with 
D, vertical 
cells, 
A, B200:1. C, D 350 :1. 
