MELANOSPERMEA. Be) 
in -length, and although, like all the Fuci which turn nearly black in 
drying, F. vesiculosus, in the living state, and during the fruiting 
season, is of a fine olive, inclining to green, the midrib being very distinct 
and of a darker tint, the air- 
vessels a pale yellow, and 
the terminal receptacles, 
which are elliptical and 
somewhat wart-like, are a 
bright orange. The illustra- 
tion shows the situation of 
the air-vessels on the frond 
to the left. The lateral divi- 
sion on the right is termi- 
nated with receptacles. 
Halidrys siliquosa (Fig. 38), 
or as its name literally sig- 
nifies, ‘‘ Podded sea oak,’’ is 
a curious and very interest- 
ing plant. When cast ashore 
from deep water, this is a 
very handsome species, and 
it is much to be regretted 
that in drying, it not only 
loses its fine olive tint and 
becomes perfectly black, but 
in the course of a short time after it has been put away in the herbarium, 
the salt which is retained in its densely cellular tissue, oozes out of the 
pod-like receptacles and disfigures the specimen. The only way to avoid 
or to check this annoyance, is to soak the plant in fresh water for some 
hours before drying it, and then to place it between towels and keep it so 
for some time before finally drying and pressing it. Our illustration is 
from a terminal branch of a plant which was about four feet in length. 
The fronds arise from a small expanded disc, and vary in length according 
to the depth of water in which they grow. A stunted but pretty variety. 
about a foot in length, is met with in rock pools about half-tide level. 
The fruit is produced in long-stalked receptacles, which are somewhat 
constricted at the septa or divisions, the seed-vessels being made up of a 
series of chambers having distinct transverse lines of separation, each 
siliqua, or pod, being terminated by a mucro or projecting point. 
Another curious species of fucus, of a fine clear olive colour which 
turns black in drying, is the plant called Pycnophucus tuberculatus, 
in Fig. 39, the fronds of which are from 10in. to 14in. high, rising from 
creeping fibrous roots which spread over the bottom of rock pools, and in 
some situations form perfect little submarine groves. Air-vessels are 
represented rarely present in this species, but when they are, as seen in 
the terminal branch of our illustration they are produced at the base 
Fic. 39. Pycnophycus tuberculatus. 
