234 
POPULAPv FIELD BOTANY, 
vegetable productions. They are parasitic, 
growing principally on dead wood, leaves, and 
decaying animal matter, reducing these sub- 
stances to dust, and forming rich soils for the 
use of other plants, besides clearing away 
what is useless, or might be injurious if the 
process of decay were very slow. 
" Some species are quite minute, others of 
large size. Of the former the mould on 
cheese is an example ; also the rust in wheat, 
which is a fungus growing on the inside of 
the grains. The dry-rot in wood is also a 
species of this family. It is very destructive 
to ships and the timber of houses. A few are 
good for food, as Mushrooms, TrufHes, and 
Morels : the former is well known ; the two 
latter grow underground, and dogs are taught 
to hunt for them by the smell, which is power- 
ful. When thoroughly made to understand 
the scent, they will scratch on the ground 
underneath which they grow, and thus bring 
their situation to light. The Mushroom may 
be distinguished from the Toadstool by the 
lamellae, or divisions on the under side of the 
cap, being pink when young, and becoming 
brown in an old state. ,There is an immense 
variety of Fungi, many very handsome in 
appearance, being crimson, bright orange, or 
the most delicate dove colour, and of all 
shades. A few have an exceedingly unplea- 
sant smell, and may be discovered by this 
means in the woods where they grow. In 
form they differ much ; many are very ele- 
gant, being like a miniature parasol ; others 
much thicker and rounder at the top ; some 
appearing to have no stalk, a mere round ball. 
The interior of some genera is divided into 
lamellae, or thin plates, as in the Mushroom ; 
in others it has many pores, and forms a sub- 
stance like sponge. 
" Alg^e. Sea-weeds. Plants growing under 
water, both fresh and salt, with the stem and 
leaves combined into lobed divisions, some so 
fine as to resemble hair. 
" A few of the plants of this order are 
found in fresh water, as the green slimy mat- 
ter in ponds. Ulva thermalis grows in hot 
springs also ; but the Sea-weeds are much 
more interesting, and we will confine our 
attention to them. They are often passed 
over as of little importance, but many are dis- 
tinguished for their beauty as well as their 
utility. Alg£e exist in all parts of the ocean, 
but they vary in different regions. They are 
in general attached to various substances, such 
as stones, rocks, shells, &c., though some are 
always free and floating. The usual colour is 
olive-brown, or green, but many are of a bril- 
liant red, and others nearly black. They 
differ as much in size as terrestrial plants. 
some attaining a great length. The Chorda 
Jihmi, found in bays of the Orkney Islands, is 
occasionally thirty or forty feet long, often 
impeding the passage of the fishermen's boats. 
An American species has been procured which 
measured a thousand or fifteen hundred feet. 
They must grow with great rapidity, for rocks 
that have been completely cleared are found 
again covered in six months, and some of the 
specimens had grown six feet long during 
that pei-iod. 
" From several species of Sea-weeds Keljj 
is derived, which is of such use in the manu- 
facture of glass and soap. They are reduced 
to ashes by burning, and this gave formerly 
to very many poor people an employment, 
which was the principal means of support in 
the Hebrides ; but lately a superior kind, pro- 
cured from a plant growing on the coast, lias 
been brought from Spain, and the demand for 
kelp has much decreased. 
" Many Sea-weeds are used for food ; the 
Rhodomenia palmata is called Dulse by the 
Scotch, and JDillesk by the Irish, and is eaten 
in both countries. One or two species of JPor- 
phyra and Ulva are brought to table under 
the name of Laver ; also Alaria esciilenta, 
known in Scotland by the name of hadderlochs 
or honey-ware. In Ireland the Chondrus 
crisjms, called B-ish Moss, is an article of 
food. It forms a kind of hlanc-mange, which 
is very strengthening. The Fucus vesiculosus, 
which is so very common on all our coasts, 
produces, by burning, the valuable medicine 
called Iodine, which can also be procured from 
sea-water. All Sea-weeds are useful as ma- 
nure, and are, therefore, extensively gathered 
for that purpose. 
"I will close this account with a descrip- 
tion of an easy method of preserving Sea- 
weeds, particularly the delicate kinds ; and 
a collection nicely preserved and arranged is 
very interesting. The specimens being brought 
home, (and it is of no consequence if they 
have shrivelled or become dry, as they soon 
expand again when placed in water,) must be 
put one by one into a large basin of clean 
water. Have ready writing paper divided 
into pieces, (a quarter of a sheet is a conve- 
nient size ;) then, when the weed is nicely 
expanded, and the dirt washed from it, place 
under it the piece of paper, and when arranged 
as required, raise them both out of the water ; 
then drain off the wet, and place them between 
two dry sheets of common paper, subjecting 
them to a slight pressure. The Sea-weed 
will adhere to the paper, causing no further 
trouble, and the specimens may be arranged 
in a book of blank leaves, the name being pro- 
cured, if possible." 
