'03 



CLASS CKYPTOGAMIA. 



.^5 



presented (Fig. 

 155) with a delin- 

 eation of three 

 kinds of Fuci.* 

 a, is FucDs nodo- 

 5?<5,( knobbed fu- 

 ciis ;) 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, h, Fucus ve- 

 friculosus, (bladder fucus;) here the air-bladders are mostly axillary, 

 and at the sides of the midrib. It varies in lenfjth from one to four 

 feet. On account of its mucilaginous property ft 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 ; this has a beautiful ser- 

 rale frond. 

 The Fucijt on 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 a/)o;/iec/a, in which the seeds are contained^ 

 this may be seen in the follo^\lng dchneation Fig 156, a, represents 



a lichen, of a leaf- 

 like appearance -, 

 here the apothe- 

 cia imbedded in 

 the leaves are ve- 

 ly apparent, b, is 

 a lichen resem- 

 bling a drinking- 

 glass. c, is the 

 1 ein-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 Orchal, 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. i 

 ^ I'uci is the plural of Fucus. 



9, 10, 11. 



Ihree kinds of Fuci— Kelp— Lichena— Explain Pig. 15G— Uses of the lichens 



