174. BRITISH MARINE ALGAE. 
divisions of the forked segments. When the plant is in fruit the spores 
are produced in these mamille or leaflets, which are sometimes so abundant 
that the manipulator is sorely puzzled in mounting his specimens effectively. 
The colour of this species is a dark purple, but the plant is so frequently 
exposed to strong sunlight, that luxuriant specimens are often met with 
in the growing state, exhibiting tints of olive, dark brown, black, and, 
sometimes, even a decided shade of green. The fronds rarely exceed 4in. 
in length. The species is perennial and is found pretty generally through- 
out the year on almost all rocky shores. 
Chondrus crispus (Fig. 162) is one of the commonest and most variable 
in form of all the native British seaweeds. The French writer, Lamouroux, 
figures no less than thirty-six different varieties. On our own shores 
the size of the fronds and the breadth of the segments seem to me to 
depend very much on the situation in which the plant is found growing. 
The larger and broader forms are generally met with near high-water mark, 
and particularly so where the plants are exposed to the influence of a 
fresh-water stream, while at low-water mark, or in deep rock pools, the 
fronds, although produced in large bushy tufts, are generally extremely 
narrow throughout. Our illustration represents two widely different 
forms of this species, both being considerably reduced in size; a, is from 
a finely grown plant with broad spreading lobes, somewhat like those of 
Phyllophora Brodici (Fig. 150) ; b, is from a plant with narrow segments ; 
the tuft from which these fronds were taken grew outside a rock where it 
was exposed to the swill and dash of the waves. All the forms of this 
thick cartilaginous species may be easily distinguished. The fronds arise 
from a crisp discoid base, having at first a narrow cylindrical stem, 
which gradually flattens and increases in breadth, from which very 
suddenly the lobed segments are produced, most of which are repeatedly 
forked, the axils of all being invariably and distinctly rounded. The tips 
are obtuse or truncated, besides being what is termed emarginate, which 
means depressed at the margin here and there, rather than cloven, znd one 
side or other of all the divisions, is constantly crisped or inclined to curl 
round, a peculiarity which is referred to in the specific name. The fructi- 
fication consists of prominent tubercles, which not only emit their spores 
at maturity, but fall away from the plant, leaving round hollow spaces in 
the frond; sori or groups of tetraspores are immersed in the fleshy sub- 
stance of the plant, and favellidia are also sometimes found ; these consist 
of masses of minute spores which are imbedded in the frond, but are 
different in structure to the tubercles, or, more properly speaking, 
nemathecia, which rot, or at least, drop off the fronds at maturity. The 
colour of this species is as variable as its forms are numerous; but in 
shady rock pools, where it is occasionally visited by gleams of sunlight, 
the fronds exhibit a mixture of dark red and purple, and the margins 
and tips of the divisions are, at times, beautifully iridescent. As the 
plant advances towards high-water mark, its colours are more sombre, 
being generally a dull brownish-red, or sometimes olive-green, and in 
