40 BRITISH MARINE ALG. 
points of difference which I have observed in all stages of its growth, 
sufficient, in my opinion, to establish it as a species distinct from L. sac- 
charina. The substance is more delicate, the colour paler, inclining to 
a greenish yellow ; the stem much shorter, even in older plants, and the 
base of the frond, where it expands from the stem, invariably wedge-shaped ; 
the frond itself being of a more equal width throughout, but tapering 
gradually towards the tip. Itis usually found in rock pools about half-tide 
level. A frond of this graceful plant is represented in the centre of Fig. 
44. It was growing in society with a tuft of Chorda lomentaria, a species 
which will be described shortly. L. fascia (Fig. 45), the band or ribbon 
laminaria, always grows in tufts, and mostly in rock pools where there 
*are little sandy nooks, in which it loves to dwell. The stem is very short, 
and expands gradually into the membranaceous dark olive frond, usually 
from 4in. to 10in. long, but rarely more than an inch in breadth. Fig. 45 
represents a very characteristic tuft of this species. L. debilis is a variety 
of this species; it may be known by its greater breadth, the frond 
expanding from the very short stem much more suddenly. This variety is 
occasionally mistaken for narrow forms of Puncturia latifolia (Fig. 65), 
from which, however, it may be distinguished, with the help of a lens, 
by its densely cellular structure, Punctaria having a reticulated or 
network-like surface, and generally dotted over with sor or groups of 
spores. 
The species of Laminaria already described are, in all stages of their 
growth, long, simple, or undivided plate-like fronds, produced from a solid 
cylindrical stem ; but the two, which I am about to describe, are (except in 
very early growth, when produced from spores) cleft into numerous long 
strap-like segments, a short distance above that portion of the frond 
which expands abruptly from the thickround stem. Fig. 46 represents the 
well-known species L. digitata, taken from a small but very characteristic 
plant which grew on the Castle rocks at Hastings, a considerable distance 
above low-water mark (hence its small size), the ordinary habitat of this 
species being from extreme low-water mark to several fathoms deep. In 
our illustration the lower part of the frond is seen to be very much bulged 
out, the plant in fact being about to produce a new frond—the lower por- 
tion, in the ccurse of time, expanding, lengthening, and separating into a 
digitated frond, precisely similar to the upper part, to which it is still 
attached, but which gradually turns black and falls off as the new frond 
approaches maturity. Fig. 47 represents the variety Stenophylla, or 
narrow-leaved Laminaria, the frond being usually cleft into two or more 
narrow segments down to a very short distance above its long round stem. 
The roots or holdfasts of these large seaweeds grasp the rocks so firmly as 
to defy all efforts to remove them. I have frequently pulled away in 
vain at an unusually fine or perfect plant; the frond or stem even 
breaking away, but not a single grasping fibre relaxing its hold. ZL. digitata 
is the plant which, in addition to Rhodymenia palmata, is sold in the 
streets of Edinburgh and elsewhere in Scotland; the people who carry 
