356 PLANTS, SEEDS, AND CURRENTS 



tudes, and 11 per cent, in the southern portion of the continent 

 (pp. 333-5). 



3. The parallelism between Sphagnum and Car ex is strikingly- 

 illustrated in the connections of South America with the rest of the 

 globe. In both genera there is the streaming of species from the cold 

 latitudes of the north along the line of the Rocky Mountains, across 

 the highlands of Central America, and down the Andes, reaching to 

 Fuegia (pp. 335-8). 



4. The connections of South America with the Australian and 

 New Zealand region may thus be summarised. With both genera a 

 few of the species, that have reached the Southern Andes and Fuegia 

 from high northern latitudes have been found also either in Australia 

 or in New Zealand or in both. But whilst the two species of Sphag- 

 num concerned must have been received by each region from northern 

 latitudes on the same side of the globe, this can only be inferred for 

 three of the six Carices involved. The other three species probably 

 crossed the Southern Ocean, one from Fuegia to New Zealand and 

 another from Australia or New Zealand to Chile, the data for the 

 third being insufficient for the purpose of distinguishing between the 

 giver and the recipient (pp. 339-40). 



5. The Car ex and Sphagnum connections between South America 

 and Africa are of the slightest. A single South American Sphagnum, 

 found also in North America, occurs in Central Africa; whilst a 

 single Carex, also North American and Eurasian, connects South 

 America with South Africa (pp. 341). 



6. The African Sphagnum and Carex floras are then discussed; 

 and here again the behaviour of the two genera offers a striking 

 parallel, since they illustrate in a similar way that remarkable isola- 

 tion which Africa so often exhibits both in its flora and in its fauna. 

 Whilst the European species of Sphagnum have crossed the Mediter- 

 ranean only to reach Tunis and Algeria, the Carices from the north 

 have in nearly all cases been rolled back by the obstacles presented 

 by the Atlas and the Sahara, only a few penetrating to the south of 

 the continent (pp. 341-2). 



7. Both genera display a like degree of endemism in Africa, ex- 

 clusive of the Mediterranean province, only about 20 per cent, 

 of their species occurring outside the continent. But in the case 

 of the Peat-mosses (Sphagnum) this cannot be taken at its face- 

 value. Whilst the Sphagna connecting South America and the 

 Australian region with the outer world range over much of the globe, 

 most of the African Peat-mosses that extend beyond the continent, 

 as here defined, do not reach further than Madagascar and the 

 Mascarene Islands. Africa possesses only one other link with the 

 other continents in a solitary North and South American species 

 that has apparently a limited distribution in the Lake District. As 

 far as the Peat-mosses are concerned, Africa compared with South 

 America and Australia is a lonely continent. As regards the African 

 Carices, although the proportion of species found outside the region 

 is about the same as in Sphagnum, the continent is brought more 

 in touch with the outer world by its connections, nearly all the species 

 concerned being wide-ranging Eurasian species that may in rare cases 



