36 HANDBOOK OF BRITISH MOSSES. 



and to the southern parts of South America, besides spreading 

 slightly northwards. At the same time tropical forms are few 

 in number, not exceeding five, dispersed througb Bourbon, 

 Mauritius, Java, Tahiti, and the Indian continent. About 27 

 Tasmanian Mosses occur in South Africa, but not generally 

 belonging to the southern types. More tropical forms indeed 

 might have been expected, as there is no severe frost to destroy 

 the young plants, should spores by any accident have been 

 wafted into the country. 



A very remarkable deviation from general laws occurs in 

 the centre of Germany. In some situations the great boulders 

 with which the plain is scattered produce alpine species of 

 Moss, as if brought during the glacial period from some dis- 

 tant regions. It is at once obvious that such species as 

 Andreaa Rothii, Catoscopium nigritum, Grimmia trichophylla 

 and 0. leucophylla are not the natural produce of the plains 

 of Germany, and these are not the only species which show 

 similar anomalies in geographical distribution. 



The following orders of Mosses contain no European spe- 

 cies, though they combine, for the most part, southern forms, 

 together with others which may be considered Tropical or 

 Subtropical, Syrrhopodontei, Hydropogonei, Octoblepharei, 

 Leptostomei, Rhizogoniei, Phyllogoniei, Hypopterygii, Racopi- 

 lacei. Fabronia has two European species amongst numerous 

 exotics. 



With the exception of one or two Mosses in amber, we have 

 no certain information as to their occurrence in what are com- 

 monly called geological formations. 



