230 SUMMARY OF CURRENT RESEARCHES RELATING TO 



economic uses as dye-stuffs or as food. He then gives a more particular 

 description of Gladoniir. He recognises three genera, Pycnothslia, 

 Cladonia, and Gladina, which most lichenologists include under one 

 genus, Cladonia. He pronounces against the theory of a symbiosis 

 between Fungi and Algaj as an explanation of the Lichen thallus, and 

 strongly advocates the use of reagents as an aid in the determination of 

 species. 



Habitat of Lichens.* — W. West publishes a note on Physcia 

 paristina, which had been recorded by Wheldon and Wilson as growing 

 with great luxuriance on cow-sheds. His own observations agree with 

 those of these two collectors, and he considers that the presence of nitro- 

 genous matter — which would be conveyed as dust to the roof of such 

 buildings, to walls on road-sides, etc.- — probably accounts for the presence 

 of this lichen in these situations. Maritime rocks are another favourite 

 habitat, the desired nourishment being supplied by the droppings of sea- 

 birds. 



Anatomy of the Genus Usnea.f — Fritz Schulte has carefully worked 

 through several species of this genus, and gives the histology of the 

 thallus and the apothecia. The fibrils, he finds, repeat the anatomy of 

 the main axis ; a strong sclerotic central axis is characteristic of all the 

 forms. This strand is repeated in the fruits as a sub-hymenial layer. 

 The cortex is formed of parallel hyphas. In the young fruits he found 

 the ascogones, but, with the exception of one very doubtful case, he 

 found no trichogyne. Schulte tested also for chemical properties. 

 Barbatin acid was present in large quantities in Usnea ceratina, sparingly 

 in U. lonyissima. It was absent in all the other species examined. 

 Usnea acid was found only in U. microcarpa, U. Schraderi, U. cornuta, 

 U. scabrata, U. plicata, and U. dasypoya. It forms a red colour with 

 potash ; crystals of calcium oxalate were deposited on the hyphre of all 

 the species examined. 



Malme, Gust. O.A.N. — Beitrage zur Stictaceen Flora Feuerlands und Pata- 

 goniens. 



[A short account of the family, and a list of species collected by the Svenska 

 expedition in Fuegia and Patagonia.] 



Wiss. Ergtbnhse der Schwed. Exp. Magellansliindern. 

 1895-97, Bd. iii.(1904) pp. 1-37 (2 pis.). 



Nils on, 13.— Die Flechtenvegetation von Eullen. (Lichen vegetation of Kullen.) 



[The character of the country is described, and a list of 137 species is given, 



none of them new ; there are some important notes and descriptions of the 



lichens.] Arlcivf. Bot, i. (1904) pp. 467-96. 



See also Hedicigia, xliv. Beibl., p. 18. 



Olivier, H. — Lichens du Kouy-Tcheou. 



[The writer describes seven Cladonix and on<; Physcia from the district.] 



Bull. Acad. Intern. Geogr. Bot, 3 se'r., xiii. (1904) No. 183, pp. 193-6. 



See also Ann. Mycol., ii. (1904) p. f>(JU. 



* Journ. Bot., xliii. (1905) pp. 31-2. 



t Beih. Bot. Centralbl., xviii. (1904) pj,. 1-22 (8 figs, and 3 pis.). 



