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of this plant that the accurate Lyngbye may weU be forgiven for
considering them to be distinct species. Few persons on inspection
of oui- plate, would suppose that the bushy and broom-like
upper figure, was identical in species with the feathery plant represented
below; even their microscopic characters are widely
dissimilar. Yet, observation, the true test of species, has traced
the one form into the other; and I possess a suite of specimens
communicated by Miss Cutler and Mrs. Griffiths, which clearly
demonstrate the transition.
Sphacelaria scoparia has been long known to botanists, having
been noticed by Baifiiin, and figured by DiUenius in Ms admirable
work. B is very common on the several coasts of Europe,
both Atlantic and Mediterranean, and probably extends to other
tropical shores besides those of the Canary Islands. I have
gathered it in two localities at the Cape of Good Hope. Eurther
south, its place is taken by an analogous form {S. funicularis,
Mont.), which is found at the Auckland Island, and in New Zealand,
in which Island some other remarkable Sphacelaria; occur.
Of these the most ciuious is S. hordeacea, whose branches are
tipped with spikes of utricles, subtended by ramuli, and closely
resembling miniature ears of barley. Other species of the genus
inhabit every zone, from North Cape to Cape Horn ; but tropical
algffi have been, as yet, so imperfectly investigated, that it is
premature to assert to which zone tbe maximum of the genus
belongs. At present the evidence is in favour of the temperate
zones of the northern hemisphere.
Professor Kützing has, in his ‘ Phycologia Generahs,’ constituted
S. scoparia the type of a distinct genus, and S.filicina^ that of
another. The grounds of such separation are, in my opinion, very
insufficient to warrant the dismemberment of so natural and well
defined a group as the Sphacelaria; of Lyngbye appear to be.
F ig . 1 . S p h a c b l a b ia sc o p a e ia ; in summer :—natural size, Branchlet of
the same :—magnified. 3. S. scoparia; in vimtor-.— natural size. 4. Branchlet
of the same. 5. Cross section of the stem, surrounded by accessory
fibres;— mag
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