198 
CLASS CRYPTOGAMIA. 
Fig. 155. 
presented (Fig. 
155) with a delin¬ 
eation of three 
kinds of Fuci.* 
«, is Fucus nodo- 
sus , (knobbed fu- 
cus;) this has 
forked fronds. 
Theknobswhich 
appear in the 
fronds are air- 
bladders,- which 
render it pecu¬ 
liarly buoyant 
upon the water. This is often more than six feet long. 5, Fucus ve~ 
siculosus , (bladder fucus;) here the air-bladders are mostly axillary, 
and at the sides of the midrib. It varies in length from one to four 
feet. On account of its mucilaginous property it forms a good ma¬ 
nure ; in some of the countries of Lapland it is boiled with meal, and 
given for food to cattle, c, Fucus serratus j this has a beautiful ser¬ 
rate frond. 
The Fucijf an burning, afford an impure soda, called kelp. 
Order Lichenes , or Lichens. 
The 5th Order contains the Lichens; these are various in texture, 
form, and colour they are leathery, woody, leaf-like, white, yellow, 
green, and black. When wet, they often appear like green herbage ; 
some are seen on stones, or old fences and buildings; others with 
strong, green filaments, are suspended from branches of trees, and 
improperly called mosses. The fruit of the Lichen consists of sau¬ 
cer-like bodies, called apothecia, in which the seeds are contained ; 
this may be seen in the following delineation. Fig. 156, a, represents 
a lichen, of ale til"* 
like appearance; 
here the apothe- 
cia imbedded in 
the leaves are ve¬ 
ry apparent. 5, is 
a lichen resem¬ 
bling a drinking- 
glass. 
is the 
rein-deer moss, 
furnishing almost 
the sole food of 
that useful ani¬ 
mal, so important 
to the existence of the Laplander. In the middle of Europe it grows 
only to the height of two or three inches ; but in Lapland it some¬ 
times attains to the height of one foot and a half. 
Many of the lichens are useful on account of their colouring mat¬ 
ter, Litmus , which is so common as a chemical test for acids and 
alkalies, is obtained from a species of white lichen, called Or dial , or 
Archil , this is also used for giving a crimson colour to wool and silk. 
The powder called cudbear , used for dying purple, is obtained from 
* See also Appendix, Plate viii. Fig. 8, 9, 10, 11. 
i Fuci is the plural of Fucus.. 
Three kinds of Fuel—Kelp—Lichens—Explain Fig. 156—Uses of the lichens. 
