THALLOGENS. 241 
logical difference in the tubercles borne upon the different fronds. 
The fact seems to be that each of these tubercles is only a cavity 
or conceptacle, enclosing in the one case a fecundating apparatus, 
in the other a fruit-bearing organ; and these organs are borne 
upon separate tubercles. /ucus vesiculosus may therefore be con- 
sidered as dieceous. “The fructification of the Fucacex,” says 
M. Thuret, “is contained in small spherical cavities situated beneath 
the epiderm, called conceptacles. These are completely closed at 
irst, but open eventually ; they open at the surface of the frond 
y @ small pore or mouth, through which the reproductive bodies 
eseape, assisted by jointed and branched hairs or cilia, which line 
the conceptacle which supports the antheroids, and it is at their 
base that the spores are fixed. In certain species, spores and 
Fig. 316.—Transverse section of the Conceptacle. 
antheroids are found in the same conceptacle ; in others, on the 
contrary, these organs are produced in different conceptacles, and 
on different individuals.” 
alas male conceptacle of F. vesiculosus (Fig. 816) is found to 
: small ovoid, transparent sacs, containing a whitish mass 
emg with reddish granules. These are the antheroids which 
ag or supported upon the branched reticulated hairs 
ae ne the conceptacle. They enclose numerous transparent 
"Puscles, at first yery thin and colourless, but in time the 
R 
