NATURAL HISTORY OF PLANTS; 35 



though each of these may again nourish its own proper plants. Nay, 

 the common alpine plants, that is those that are found on the Alps 

 of Europe and Asia, seem to follow the line of perpetual snow, and 

 are met with on the plains in Greenland, Spitzbergen, Lapland, 

 Nova Zembla, northern Siberia, and Kamschatka, while in the 

 warmer regions they keep on the summits of the highest Alps. On 

 the mountains of Siberia, Lapland, Norway, Scotland, and Switzer- 

 land, on the Pyrennees, on the Apennine and Carpathian Alps, as 

 well as on the smaller mountainous chains of Germany, as in the 

 Hartz, in Thuringia, in Silesia, and Bohemia, there are many plants 

 that are common. For instance, the dwarf birch, (Betula nana), is 

 found on them all, the Siberian, Apennine, and Carpathian Alps ex- 

 cepted. May not this communion of some plants, which can only 

 be dispersed by means of winds, of birds, and other circumstances, 

 be a proof of a former connexion? Tournefort saw at the foot of 

 the mountain Arrarat, the plants of Armenia, higher up those 

 common in France, still higher those of Sweden, and at the top 

 the alpine plants, which are found at the North Pole. Similar ob- 

 servations have been made by other travellers on mount Caucasus. 



On the mountains of Jamaica Swartz found no European alpine 

 plants, but many common European mosses, such as Funaria hy- 

 drometrica^ Bryum serpillifolium, caespiiitium, Sphagnum pa* 

 lustre, Dicranum glaucum, and many others. We know that the 

 seeds of mosses are so small as to be invisible to our eyes, and that 

 it requires a high magnifier to enable us to see them. We know 

 too that they swim in the air ; may they not, therefore, have been 

 driven thither by the winds, and, finding a convenient climate, have 

 there generated 1 At least no other way of accounting for their ap- 

 pearance occurs to me. ' 



Perhaps the seeds of some lichens that grow in warm climates, 

 may be brought by the winds to u<, and by reason of our unfa- 

 vourable climate grow, but bear no fruit. This appears to be the 

 case with the Lichen caper at us, which is found in the south of 

 Europe, as in Provence, Italy, &c. on the stems of the olive trees, 

 and on the stakes that serve for the support of the vines, and almost 

 never without the fructification ; while with us, where it is so com- 

 mon, it never bears any. 



But when the two Forsters found on Tierra del Fuego, the Pin- 

 guicula alpina, Galium Aparine, Statice Armeria, and Ranunculu* 

 * B2 



