48 



LICHENALES. 



[Thallogexs. 



XXXII. 



like matter, that overruns the grass in the mornings of sprmg and autumn, of this nature, 

 and not of an animal origin. See S. 0. Veg. 318.* 



The nutritive properties of Lichens proba- 

 bly depend upon the presence of an amyla- 

 ceous substance analogous to gelatine, which, 

 accordmg to Berzelius, occurs in the form of 

 pure starch or amylaceous fibre, to the 

 amount of 80.8 per cent, in Cetraria islandica. 

 This plant, which is the Iceland Moss of the 

 shops, is slightly bitter as well as mucila- 

 ginous, and is frequently used as a tonic, 

 demulcent, and nutrient ; Ceti'aria nivahs, 

 Sticta pulmonaria, and Alectoria usneoides, 

 will all answer the same piirpose. Tripe de 

 Roche, on wliich the Canadian hitters are 

 often forced to subsist, is the name of various 

 species of Gyrophora ; several kinds of Leca- 

 nora inhabit even the deserts of Asia in 

 large quantities, and are eaten by the nomade 

 tribes of those regions. The Rein-Deer Moss, 

 wliich forms the winter food of that animal, is Cenomyce rangiferina. Parmelia 

 parietina, Borrera furfuracea, Evernia prunastri, Cenomyce pyxidata and coccifera, are 

 reputed astringents and fe- 

 brifuges, and Peltidea aph- 

 thosa an anthelmintic. Alec- 

 toria Arabum (Oschnah) is 

 said to be sedative and sopo- 

 rific. Peltigera canina was 

 once regarded as a specific 

 in hydrophobia. Sticta pul- 

 monacea is used in Siberia 

 for giving a bitter to beer, 

 and in this coimtry is em- 

 ployed, under the name of 

 Lungs of the Oak, as a nou- 

 rishing diet for weak persons. 

 Evernia ATilpina, called Ulf- 

 mossa by the Swedes, is 

 behoved by that people to 

 be poisonous to wolves ; but 

 this requires confirmation. 

 See De Cand. Essai Med. 

 318, and Agardh, A]:>?i. 94. 



According to the chemists, 

 Lichens contain several pe- 

 cuhar principles ; such as 

 Cetrarine, Picrolichenine, 

 Stictine, and Variohne, which 

 are bitter ; and the colour- 

 ing matters called Orcine, 

 Erythrine, Parmelochro- 

 mine (also called Vulpulme 

 and Vulpinic acid), Strych- 

 nochromme, Strychnery- 

 thrine, Lecanorine, &c. : and 

 finallv, from Usnea florida, 



Fig. XXXIII. 



* Nothing, however, can be more heterogeneous than the mass of genera collected by Fries under 

 the unfortunate name of Byssack^. Many of them are spurious genera, others true Fungals, a few 

 anomalous Lichens, and a small portion not easily arranged under Fungals, Algals, or Lichens. An 

 excellent notice will be found by Dr. Montague in the History of Cuba, and the latest information on 

 the subject in the article Byssacees in the new Diet. d'Hist. Nat. By excluding such genera as Cilicia 

 and Ccenogium, which the example of Parmelia gossypina will justify us in uniting with Lichens, we 

 have remaining a very natural, though small group, which may be distinguished under the name of 

 CoUemaceas; and Dr. Montagne, who has lately had some correspondence on the subject with 



Fig. XXXII.— Cetraria islandica : a a. its shields ; b. a shield magnified and divided vertically. 

 Fig. XXXIII.— Sticta pulmonaria, or Lungs of the Oak. 



