50 HISTORY OF BRITISH MOSSES. 



higher organizatiorij with reference to their altitudinal range 

 on mountains, as we find that the species or forms of colder 

 cKmates gradually appear as we ascend the mountains in 

 tropical countries ; and in Britain we find that the species 

 abounding withui the polar circle are found on the summit 

 of our Scottish mountains, though but of moderate height. 

 Jamaica, for instance, is an island on the lowlands of which 

 verv few mosses have been found, wlule on its Blue 

 Mountains Swartz found a great variety, differing in many 

 respects, as might be expected, from the European fiora. 



While however we have the individuals more numerous, 

 there is by no means such a diversity of form among Mosses 

 as among plants higher in the scale. This will easily be 

 understood when we consider the small proportion they 

 bear in statistical tables; and to illustrate this fact we may 

 mention that there are but a very few species natives of 

 Britain that have not been detected on the continent of 

 Europe,. and vice versa. What is still more singular is the 

 fact that the great continent of Nortli America, especially 

 in the corresponding parallels of latitude — so much further 

 removed from us — contains a muscal flora still more re- 

 sembling that of the British Isles. Those who have exa- 

 mined the collections made by the lamented Drummond, 



