6 INTRODUCTION. 



degree of heat which some forms of vegetation are capable of 

 sustaining, and which, to some species, indeed, appears a natural 

 and even necessary condition. A hot spring in the Manilla 

 islands, which raises the thermometer to 187, has plants flou- 

 rishing in it and on its borders. In hot springs near a river of 

 Louisiana, of the temperature of from 122 to 145, have been 

 seen growing not merely the lower and simpler plants, but 

 shrubs and trees. In one of the Geysers of Iceland, which was 

 hot enough to boil an egg in four minutes, a species of Chara 

 has been found growing and reproducing itself ; and vegetation 

 of an humble kind has been observed in the similar boiling 

 springs of Arabia and the Cape of Good Hope. One of the 

 most remarkable facts on record, in reference to the power of 

 vegetation to proceed under a high temperature, is related by Sir 

 G. Staunton, in his account of Lord Macartney's embassy to 

 China. At the island of Amsterdam a spring was found, the 

 mud of which, far hotter than boiling water, gave birth to a 

 species of Liverwort (. 32). A large Squill bulb, which it was 

 wished to dry and preserve, has been known to push up its 

 stalk and leaves, when buried in sand kept up to a temperature 

 much exceeding that of boiling water. 



Even the extreme of cold is not fatal to every form of vegetable 

 life. In the realms of perpetual frost, the snow which covers 

 mountains and valleys, and whose surface scarcely yields to the 

 influence of the solar rays at midsummer, is in some places 

 reddened for miles together by a minute vegetable, which grows 

 in its substance, and has been supposed, from its very rapid in- 

 crease, to have fallen from the sky. This will be hereafter 

 described under the name of Red Snow (. 48), which is that 

 commonly applied to it. The Lichen which forms the winter 

 food of the Rein-Deer (. 39), grows entirely buried beneath 

 the snow ; and its quantity may be judged of, by the number of 

 the animals which find in it their sole support, during a consider- 

 able part of the year. 



