106 
THE SEAWEEDS 
Family ECTOCARPACEAE. 
Frond filiform, more or less branching, mostly of one row of cells, the 
growth in length produced by intercalary division of the cells. Mostly 
epiphytic but sometimes attached to rocks. Reproductive organs, uni- 
locular and plurilocular sporangia, occupying the place of ramuli, or 
immersed and formed from the vegetative cells. 
ECTOCARPUS Lyngbv. 
Fronds filiform, branched, articulated (something of the habit of 
Cladophora ) . Sporangia external, occupying singly the place of lateral 
Fig. 57. — Ectocarpus . — Germination of swarmspores from plurilocular 
sporangium — (a) shoot of five days’ growth; (b) part 
of shoot after eighteen days (after Kylin) ; (c) portion 
of mature plant of E ctocarpus confervoides with one 
unilocular and one plurilocular sporangium. All much 
enlarged. 
ramuli. Unilocular sporangia globose or ellipsoid, with an apical pore. 
Plurilocular sporangia ovoid or pod-like, wdth several longitudinal rows 
of locelli. 
E ctocarpus siliculosus (Dillw.) Lyngby. 
Fronds flaccid, at first affixed, then free floating. Dull green. Unilocular 
ovoid, sessile or with a short pedicel of one joint. Plurilocular conoid- 
subulate, often terminating in a hair. To 30 cm. high, yellowish brown olive 
in colour. Monoecious. 
Ectocarpus confervoides (Roth) LeJol. 
Very like the preceding and hard to distinguish from it. Always affixed. 
Plurilocular sporangia not terminating in a hair, shortly subulate or 
fusiform. 
Both species are cosmopolitan and may be found anywhere. 
