INTRODUCTION" TO THE REPORTS ON INSULAR FLORAS. 67 



South Trinidad. — This island was covered, in parts at least, with wood, even as late 

 as the middle of the present century. Now the trees are all, or nearly all, prostrate and 

 dead ; and the living vegetation, as far as known, is restricted to about a dozen species of 

 flowering plants and ferns ; but it has not been explored by a botanist. Independently of 

 the existing vegetation, it would be interesting to ascertain the relationship of the trees 

 which formerly clothed the hill-sides. The few plants known are distinctly Brazilian in 

 character, with the exception of one fern, which had previously only been collected in St 

 Helena. 



Tristan da Cunha Group, and St Paul and Amsterdam Islands. — These two distant 

 groups are coupled, because, as already explained, the plants forming the mass of the 

 vegetation are of the same species in both cases. They are only two in number. One is 

 a stout reed (Spartina arundinacea) , which is confined to these islands, and has its 

 nearest ally in a South-eastern American species ; and the other is Phylica nitida, a shrub 

 or small tree, also found in the Mascarene Islands, and belonging to a genus numerously 

 represented in Extratropical South Africa, with a few species in Madagascar, and one 

 endemic species in St Helena, and unknown elsewhere. The distribution of Phijlica nitida 

 is specially remarkable, inasmuch as it is unknown in Africa, and perhaps as nearly related 

 to the St Helena species as any. The small number of other flowering plants in these two 

 groups of islands consists partly of endemic species of genera more or less widely diffused 

 in the south temperate zone or beyond, and partly of species of wider range. 



Tlte Chain of Islands from the Prince Edward Group to the Macdonald Group. — 

 From our analysis of the distribution of the vascular plants found in these islands (Part 

 II., p. 250), it will be seen, that in spite of the great distances separating the groups, the 

 vegetation is essentially the same throughout, and a part of that characteristic of the 

 coldest southern region of flowering plants generally. These facts, considered in relation 

 to the means by which the plants might be dispersed, all point to a former great land- 

 connection, and this is the view taken by Sir Joseph Hooker and Mr Moseley. Further, 

 the fuller details of the Antarctic Flora a few pages back confirm the close relationship 

 existing between the vegetation of the most distant points of the coldest southern region. 

 The Antarctic drift and* other agencies may possibly have conveyed the seeds of the 

 plants growing in the chain of islands under consideration. "Wallace employs all the 

 evidence adducible to prove a former land-connection between New Zealand and Australia 

 by way of Lord Howe's Island, and doubtless his arguments are sound ; but he is content, 

 perhaps from having less deeply studied this part of the subject, with a comparatively 

 broken connection with America to account for the American element in New Zealand. 

 The extreme poverty of the present vegetation of the islands in the South Indian Ocean 

 might be put forward as an argument in favour of original isolation ; but the evidence of 



