80 NATURAL ORDERS AND 
ORDER CX. LICHENES.—Jvss. 
Perennial plants often spreading over the surface of the earth, or 
rocks or trees in dry places, very variable in their form and texture, 
consisting of a thallus, in the form of a lobed and foliaceous or hard 
and crustaceous or leprous substance, sometimes it is erect, fruticulose, 
and branched, at others pendent, variously coloured, rarely green, the 
substance of the thallus is sometimes simply cellular, but generally 
it is composed of cortical and medullary layers, the former being 
simply cellular, the latter both cellular and filamentous. Fruetifi- 
cation of two kinds. 1. Sporules lying in membranous tubes or 
thece, immersed in nuclei of the medullary substance, which burst 
through the cortical layer, mostly becoming of a different colour 
harder, and are in the form of little disks of various forms, and called 
apothecia ; 2. cellules of the medullary layer of the thallus bursting 
through the cortical layer in the form of wart-like excrescences. 
ORDER CXI. ALG#.—Juss. 
Leafless aquatic plants, without any distinct axis of vegetation, 
frequently having an animal-like motion, and consisting either of 
simple vesicles, lying in mucus, or of articular filaments, or of lobed 
fronds, formed of uniform cellular tissue. Fructification either 
apparently wanting, or contained in the joints of the filaments, or 
deposited in thece of various forms, size, and position, caused by 
dilatations of the substance of the frond. Sporules with no proper 
integument, in germination elongating in two opposite directions.— 
Plants of a sub-pellucid texture, often beautifully cellular, or tubular, 
and of a bright red or pink colour, frequently green or brownish, after 
having been dried a considerable length of time, they will revive on 
immersion in water 
ORDER CXII. FUNGI.—Joss. 
Plants consisting of a congeries of cellules, among which filaments 
are occasionally intermixed, increasing in size by addition to their 
inside, their outside undergoing no change after its first formation, 
always springing from organised and generally decayed or decaying 
substances. Sporules lying either loose among the tissue, or enclosed 
in membranous cases called sporidia.—Plants varying extremely in ~ 
substance and duration, generally soft and juicy, sometimes exceedingly 
hard, with or without a central gelatinous nucleus, or dry and powdery. 
