The Present Flora of Britain. 19 



distribution of these is too peculiar to permit of any 

 attempt at explanation in the present state of our know- 

 ledge as to the former range of these species. Spiranthes 

 Romanzoviana occurs in Cork, and in North America 

 and Kamtschatka ; Sisyrinchium angustifoliuni is found 

 in bogs in Gal way and Kerry, and also in Arctic and 

 Temperate North America ; Eriocaulon septangitlare is an 

 aquatic plant occurring in Skye and the West of Ireland, 

 and also in North America. 



From the above notes it will be seen that Britain shows 

 signs of a geographical distribution of plants largely in- 

 dependent of that due to climate ; or, perhaps we should say, 

 not governed by existing climatic conditions. The cause of 

 these peculiarities will be best discussed when we have 

 examined into the means of dispersal possessed by dif- 

 ferent plants ; but it will be as well at once to say that 

 the subject is beset with difficulties, and at every turn we 

 meet with instances of anomalous distribution, such as 

 make a botanist inclined to suggest ' accidental introduc- 

 tion by man ' were it not that many of the species are 

 marsh or woodland forms, long established and most un- 

 likely to be brought by human agency in any form. Per- 

 haps future research may show that many of the outliers 

 were once less isolated, and that the present distribution 

 is not so unaccountable as it seems. Such has already 

 been shown to be the case with many mammals and 

 mollusca, which geology proves had once a much wider 

 distribution; but the flora of our Later Tertiary deposits 

 has not yet been collected and studied so thoroughly as 

 has the fauna. 



