MELANOSPERME&. 77 
is more frequently met with eastward of Plymouth Breakwater, where I 
have occasionally dredged it of large size, but in no instance have I ever 
detected fruit. The very curious and minute species known as S. ser- 
tularia, is parasitical on algz which grow in deep water. It is rarely met 
with, perhaps on account of its small size and the depths in which it loves 
to vegetate. Dr. Harvey considers it to be merely a deep water variety of 
the foregoing species. It is a very much smaller plant, and the branches 
and ramuli are shorter and generally spread out at right angles with 
the stem. S. scoparia is a large coarsely branching plant found in most 
seas; on the southern shores of the Isle of Wight its large tufted fronds 
frequently strew the beach in great abundance. The summer and winter 
conditions of this species are widely different. In early growth, and during 
the summer its tufted branches are thick and bushy, resembling little 
brooms, but at the close of the season its superabundant branches and 
LEEK 
= 
L 
Fic. 78. (a) Terminal branch of a seaweed, with a tuft of Sphacelaria 
cirrhosa. (b) Plume from the same, magnified. 
ramuli fall away, totally changing its character, specimens of which bear 
occasionally such a striking resemblance to loosely branching forms of S. 
filicina, that many an inexperienced botanist has been deceived as to its 
identity. Fig. 78 (a) represents one of the varieties or forms of the species 
S. cirrhosa, parasitical on a terminal fork of a seaweed, and beside it (b) one 
of the plumes of which this pretty little plant consists. In some varieties 
of this species the filaments form little star-like tufts, as in the illustration ; 
in others the tufts are globular in form and densely branched. I took this 
variety many years ago in great plenty, as it was floated in by the tide on 
the shore of the Great Cumbrae Island. Every specimen I picked up on 
that occasion was in fruit. The spores are like little round balls seated 
near the base of the branchlets, generally one or two, opposite or some- 
times close together. Another very tiny variety of this plant I have taken 
