LICHENES — FUNGI. 647 



Europe, also North America and the Antarctic regions. It is used as 

 a tonic. By the action of sulphuric or hydrochloric acid on it, 72 per 

 cent of grape sugar is procured. Gladonia rangiferina, is a Lichen 

 upon which the Eeindeer feeds. Several species of Gyrophora con- 

 stitute the Tripe de Roche, on which Franklin and his companions 

 subsisted for some time. Many other Lichens, such as Sticta pul- 

 monaria, Lung-wort or oak-lungs, and species of Lecanora, furnish 

 articles of food. Roccella tinctoria from the Canaries, R. fuoiformis, 

 B. hypomecha, furnish valuable dyes, under the name of Orchil or 

 Archil. The dye procured from them, and from other Lichens, is 

 called Litmus. Lecanora tartarea supplies the dye called Cudbear. 

 Parmelia parietina contains a yellow colouring matter called Parietin 

 or Chrysophanic acid. Some species of Variolaria contain a large 

 quantity. of oxalate of lime. Some plants of the order are aromatic. 



Order 222. — Fungi, the Mushroom Family. (Hysterophyta of 

 Endlicher.) The plants belonging to this order consist of cells, some- 

 times round, sometimes elongated in the form of filaments, either 

 placed closely together or separated. They are variable in their con- 

 sistence, being soft or hard, fibrous or gelatinous, fleshy ,or leathery. 

 They never contain green gonidia like Lichens, and they rarely grow 

 in water. There exists a vegetative system called spawn or mycelium 

 [fiimini, fungus), formed of elongated, simple, or articulated filaments, 

 concealed within the matrix, or expanded over its surface, from 

 which varied forms of fructification proceed. The mycelium occurs 

 in a filamentous, a membranous, a tubercular, or a pulpy form. The 

 reproductive organs consist of spores or spherical cells (usually 4, or 

 some multiple of 4), which are either attached to the cellular tissue, 

 and supported often on simple or branched filamentous processes (figs. 

 896, 898) called sporophores {evo^a,, a spore, and ipogia, I bear) or 

 basidia ($d(!is, a, base) ; or are contained in thecse (theca, a sac), 

 cystidia (xusTig, a bladder), or asci (adxoi, a bag), (fig. 896 c), accom- 

 panied with bodies called antheridia and paraphyses. The sporophores 

 sometimes end in delicate cells bearing the spores, and called sterig- 

 mata (^erri^iyfia, a support). In the Agarics or Mushrooms, which 

 are among "the best known fungi, there is observed first a roundish 

 protuberance on the mycelium. This swelling is called the volva or 

 wrapper, and it 'gradually enlarges, containing in its interior what 

 appears afterwards as the agaric, with its reproductive bodies. When 

 the volva is ruptured, the fully-formed agaric is seen, consisting of an 

 upper rounded portion called the pileus or cap (fig. 894 c c), sup- 

 ported on a stalk or stipes (fig. 894 p). On its under surface is 

 situated the hymenium (i/i^n, membrane), or the part where the spores 

 are produced (fig. 894 h), covered at first by a thin membrane called 

 a veil (indusium or velum), which is ultimately ruptured ; and when 

 the rupture takes place at the edge of the pileus, an annulus or ring 



