INTRODUCTION. xxi 



lers to be almost the only vegetable productions. On the Nor- 

 thern border of Siberia, towards the coast of that sea, for the 

 width of some hundred versts, upon an immensely extended 

 morass, destitute of trees, the entire soil is said to be covered 

 with Mosses, which thrive although their roots are only just above 

 the crust of eternal frost ; and on which, even in summer, you 

 travel in sledges drawn by Rein-deer. In Spitzbergen, according 

 to Martens, the rocks of Schistus, rising out of the mass of ever- 

 lasting ice, are thickly clothed with Mosses. In Greenland, they 

 constitute the most numerous class of vegetables, and Crantz, a 

 celebrated traveller in that barren country, says he had counted 

 above 20 species without rising from the rock whereon he was sit- 

 ting. By the late expeditions to the Arctic regions, a great 

 number of Mosses have been brought from very high latitudes ; 

 but what seems singular is, that many appear very rarely to 

 bear fruit ; for among the specimens brought home, (of which 

 we possess the greater number,) an extremely small proportion of 

 species, comparatively, are in a state of fructification. This cir- 

 cumstance gives an additional force to the argument, that what 

 we consider the seeds of these plants are by no means necessary 

 for their increase. 



It is this universality, if we may so call it, of the Mosses ; 

 this disposition in them to grow every where, even in such spots 

 as are incapable of producing any other plants, that has much 

 contributed towards making their study a favourite occupation 

 with us. Upon the summits of our highest native mountains, - 

 upon the most lofty Alps of Switzerland, and the still more ele- 

 vated ones of Savoy and Piedmont, upon the morasses and 

 volcanic tracts of Iceland, have we received amusement and in- 

 struction, though the inexperienced eye could discover nothino- 

 more than seemingly barren wastes. 



Nor is the pursuit of these vegetables confined to the 

 summer season alone; as is the case with most other depart- 



b 3 



