OUR MARINE ALG.E. 
5 
and fill a vasculum with sufficient sea-weeds to start a respect¬ 
able collection, and to occupy a whole winter in the study of 
them. During the subsequent holiday I spent there I 
mounted about one hundred specimens, and found some forty 
different species. As the sea-weeds are arranged on a natural 
plan, it is necessary that there should be a careful discrimi¬ 
nation of all parts of a plant, that it may be assigned to its 
proper place. These parts are—the root, the frond, and the 
fructification or reproductive organs. 
The root generally takes the form of a disc, though in some 
rare instances it may be of a fibrous nature. Its office is not, 
as in other plants, to extract nourishment from the earth, but 
merely to maintain a safe position. The sea has its wild 
moods, like the aerial ocean in which we vegetate, and its 
weeds could not exist on the rocks and other places exposed to 
the violence of the waves, but for the firm grasp of their roots ; 
and tenacious as they are, many are wrenched from their hold 
and cast ashore by every storm. As the roots are not for 
nourishment, the plants seem to be, in a large measure, in¬ 
different as to the place where they grow. They fix their home 
in the sand or mud, or on the hard rock, and in many cases 
become parasitical, although not truly so, perhaps, as they do 
not derive nourishment from the other plants on which they 
grow. Some sea-weeds root themselves on fronds of their 
own species, and Johnstone and Croall report that they have 
often seen a specimen of Laminaria diyitata so completely en¬ 
veloped by a forest of young Laminaria, that the poor old 
parent was well-nigh suffocated by its own progeny. The 
Laminaria is not the only parent who is overweighted with a 
multitude of children. I have a piece of the stem of a Lam¬ 
inaria affording a home to a little happy family consisting of 
Rhodymenia palmata, Ddesseria alata, and Cladophora rupestris , 
to say nothing of the Zoophytes that had founded their colony 
there. The root of the sea-weed is always small compared 
with the size of the plant, and in some cases it is entirely 
absent. 
The fronds of our Algie have next to be considered. These 
are more or less gelatinous in their nature, for which reason 
many of the specimens adhere to paper without the aid of gum. 
I have a specimen of Porpliyra laciniata , which I mounted 
some twenty years ago, that has been tossed about in frequent 
exhibitions, but remains almost part of the paper to which it 
adheres. The gelatine gives substance to the frond, and by 
the quantity contained the plant is described. If small it is 
called membranaceous, if abundant and fluid gelatinous, and if 
firmly fixed it is said to be cartilaginous. These form some of 
