DISTRIBUTION OF SPHAGNUM AND CAREX 357 



include Australia and even North and South America in their range 

 (pp. 342-4). 



8. With both Sphagnum and Carcx more than half of the African 

 species belong to the youngest, most vigorous, and largest of the sub- 

 divisions of the two genera. Primocarex, the oldest subgenus of the 

 Carices and the nearest to the parent-type, fails altogether in Africa. 

 The facts indicate that the invasion of Africa by the Carices and the 

 Peat-mosses took place during the later stages of the differentiation 

 of those genera, and has since been followed by a period of isolation 

 extending down to the present time (pp. 344-5). 



9. The sources of the Peat-mosses and Carices of the southern 

 part of the African continent are then considered, and it is concluded 

 that South Africa has derived all its Sphagna and most of its Carices 

 from regions north, it being shown that one of the last named was 

 probably brought across the ocean from Patagonia (pp. 345-6). 



10. The parallelism between Sphagnum and Carex presented in 

 Africa and South America is also displayed in the Australian and 

 New Zealand region, the differences in the behaviour being only in 

 degree. Taking first the combined area and its connections with 

 South America, we find that the Sphagna concerned and most of the 

 Carices could have been derived from northern regions on the same 

 side of the globe (p. 347). The connection with South Africa is not 

 illustrated by Sphagnum and very doubtfully by two species of 

 Carex also found in Asia, which is probably their source (p. 349). 

 By far the most important are the Asiatic connections, which are 

 treated in detail ; but it may be here observed that all the Sphagna 

 and nearly all the Carices which are found outside the limits of the 

 combined area occur in Asia. There is no connection either with 

 Europe or North America that is not also Asiatic, all the species so 

 concerned being widely distributed in the northern hemisphere. 

 It is shown that derivation from South Africa and South America 

 is altogether excluded for the Peat-mosses and for all but 3 or 4 

 per cent, of the Carices, New Zealand having received two species 

 from South America and Australia none. Asia, therefore, repre- 

 sents the immediate source of the Australian and New Zealand 

 Sphagna and Carices (pp. 349-50). 



11. The Sphagnum and Carex floras of Australia and New Zealand 

 are then compared ; and it is elicited that whilst the degree of endem- 

 ism in each region is apparently similar in the case of Sphagnum, 

 it is much more pronounced amongst the New Zealand Carices. 

 The respective connections are then discussed (pp. 351-2). 



12. The similarity in the role played by a Sphagnal subsection 

 (Suhsecunda) in the African and Australian regions is noted 

 (p. 352). 



13. An endeavour is then made to show that the general behaviour 

 of the Carices and the Peat-mosses is in agreement with the views 

 of distribution adopted in the two preceding chapters. The close 

 parallelism between genera so unlike in their rank, so remote from 

 each other in their histories, and so different in their modes of dis- 

 persal, is a pregnant fact in distribution. It indicates a principle 

 affecting a host of other plants of the north that are often strangely 



