A very charming plant, though a common one; common, not
merely on the shores of Europe, but dispersed far and wide
through the ocean, north and south of the Line. Dr. Hooker
gathered it at Cape Horn, and Mr. Gunn has sent it from Van
Dieman’s Land. I have examined specimens from these distant
habitats, and compared them with those from our own shore,
and can detect no specific distinctions. The characters of the
species are indeed strongly marked, and once seen, cannot be
forgotten. Would that others of this beautiful genus were
equally constant! It would save botanists a world of trouble
and uncertainty. Here every articulation, without exception,
through the whole plant, bears its pair of comb-like branchlets.
Under the microscope, therefore, Cal. Plumula cannot well
be mistaken. But, notwithstanding this perfect regularity of
branching, specimens differ much in luxuriance, and consequently
in outer aspect; and we might enumerate two varieties, in one
of which the combs are twice as long as in the other, and more'
delicate.
Cal. simile of the Antarctic Flora, a native of Kerguelen’s
Land, is an instance of a closely allied, and yet perfectly distinct
species, and shows in a very forcible manner how similar two
things in nature may be, wnthout being the same; how closely
she can draw her lines without touching at any point!
Pig. 1. Oallithamnion P lumula :— of the natural size. 2. Portion of a
frond. 3. Portion of another specimen, with favelloe. 4. Eavellæ, with
surrounding plumules. 5. Plumule, bearing tetraspores on its ultimate
ramuli. 6. Penultimate ramulus from the same, with tetraspores ;— all i
or It
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