utumn, round white seeds, that, like many of the seeds of the
land, had their sugar and starch. But these plants kept far aloof, in
their green depths, from their cogeners the monocotyledons of the
terrestrial flora. It was merely the low _Fucaceae_ and _Conferveae_ of
the sea that I found meeting and mixing with the descending dicotyledons
of the land. I felt a good deal of interest in marking, about this time,
how certain belts of marine vegetation occurred on a vast boulder
situated in the neighbourhood of Cromarty, on the extreme line of the
ebb of spring-tides. I detected the various species ranged in zones,
just as on lofty hills the botanist finds his agricultural, moorland,
and alpine zones rising in succession the one over the other. At the
base of the huge mass, at a level to which the tide rarely falls, the
characteristic vegetable is the rough-stemmed tangle--_Laminaria
digitata_. In the zone immediately above the lowest, the prevailing
vegetable is the smooth-stemmed tangle--_Laminaria saccharina_. Higher
still there occurs a zone of the serrated fucus--_F. serratus_--blent
with another familiar fucus--_F. nodosus_. Then comes a yet higher zone
of _Fucus vesiculosus_; and higher still, a few scattered tufts of
_Fucus canaliculatus_; and then, as on lofty mountains that rise above
the line of perpetual snow, vegetation ceases, and the boulder presents
a round bald head, that rises over the surface after the first few hours
of ebb have passed. But far beyond its base, where the sea never falls,
green meadows of _zostera_ flourish in the depths of the water, where
they unfold their colourless flowers, unfurnished with petals, and ripen
their farinaceous seeds, that, wherever they rise to the surface, seem
very susceptible of frost. I have seen the shores strewed with a line of
green _zostera_, with its spikes charged with seed, after a smart
October frost, that had been coincident with the ebb of a low
spring-tide, had nipt its rectilinear fronds and flexible stems.

But what, it may be asked, was the bearing of all this observation? I
by no means saw its entire bearing at the time: I simply observed and
recorded, because I found it pleasant to observe and record. And yet one
of the wild dreams of Maillet in his _Telliamed_ had given a certain
degree of unity, and a certain definite direction, to my gleanings of
fact on the subject, which they would not have otherwise possessed. It
was held by this fanciful wri