THE SEA-WEEDS AT HOME AND ABROAD. 2817 
shores, and it is to the Corallines and their allies that we 
will turn for farther enquiry. Leaving, however, unwil- 
lingly, the attractive Chlorosperms we will make some ac- 
quaintance with the beautiful family of the Rhodosperms, or 
rosy-seeded algæ, plants corresponding in the tints and colors 
of their external and internal arrangements, with the ele- 
gance of their seed-vessels and seeds. In outward habit the 
Corallines present also considerable variety from the sim- 
plest and lowest in the mode of increase similar to that of the 
crustaceous lichens, spreading in horizontal concentric cir- 
cles, or gradually developing upwards and outwards in the 
form of stems and branches. On every part, encrusted in 
their lime covering which moulds itself to the joints, swel- 
lings, depressions, ridges, or into the flutings and channels 
of the surface, or surmounts the very tips in the form of 
seed-vessels, one would scarcely suppose that these elegant 
marine productions — so abundant in every tide pool, and 
fringing the deep cool grottos beneath the water-covered 
rocks, or lining with patches of pleasing and varied colors 
their sides, or laying down tessellated and mosaic pave- 
ments, by encrusted pebbles presenting to the vision variety 
springing from their secreted cements — were sea-weeds and 
marine vegetation. But an immersion in diluted mineral 
acids dispels the mystery; the usual tender and flaccid tis- 
sue of cells and pulp appear in due proportions beneath the 
covering which looks so much like the fabrications of the 
polyps, and in the absence of microscopical investigation 
these innocent plants were described and figured as ani- 
mals related to the corals, and from their smaller size and 
comparative insignificance were called Corallines. Very 
rarely found in the colder seas the one species best known at 
the north is the Corallina officinalis (fig. 75), once in ficti- 
tious repute in medicine. You cannot miss it, growing as it 
does in the pools left by the tides, and to be picked from 
the beaches attached to some shell, most usually the larger 
muscle (M. modiolus), thus indicating its range even in 
