Johnson . — Observations on Phaeozoosporeae . 137 
large number of spores each of which has a well-marked 
orange-red pigment granule. I was not able to see either 
the dehiscence of the sporangium or any movements of the 
spores. The only fertile plant I had the opportunity of 
examining was taken in ten fathoms, in August 1890, in 
Plymouth Sound. The statement, occasionally to be met 
with, that the tips of the branches in C. Cabrerae are naked, 
is due to the examination of the plant in a fertile state. In 
this state, however, microscopic examination shows that the 
tufts of hair are present though the hairs are reduced to 
their bases. Indeed there is every indication that the re- 
ceptacles are transformed branch-apices. The superficial cells 
of the thallus, instead of forming a compact limiting layer to 
the thallus, grow out into paraphyses and sporangia. 
2. Sporochntjs pedunculatus A g. 
S', pedunculatus , though rare, is much commoner than Car - 
pomitra Cabrerae , and can be dredged in tolerable plenty in 
Plymouth waters 1 . 
Trichothallic growth. The mode of growth of the thallus 
is essentially the same as in C. Cabrerae (Figs. 5 > 6). The 
thallus is filiform, pinnately branched, each branch bearing 
a number of alternating shortly-stalked receptacles. Occasion- 
ally one finds a plant in which the main stem bears the 
stalked receptacles directly, without the formation of lateral 
branches. Both main stem, branches, and receptacles have 
their tips occupied by a tuft of hairs acting as just described 
in C. Cabrerae. Fig. 2 applies almost equally well to S. 
pedunculatus. In a ripe receptacle the hairs are quite short, 
though still recognisable ; the punctum vegetationis is present, 
though no longer active ; there is everything in fact to indicate 
that the receptacle is built up on the same plan as the sterile 
branch. It is not difficult to see that the stalked receptacle 
is in reality a modified branch of the thallus, as is, less 
obviously, the case in C. Cabrerae . 
1 T. Johnson, Journal Marine Biol. Assoc., New Series, vol. I, No. 3; Flora 
of Plymouth Sound, p. 286. 
