The Scottish Naturalist. 203 



cover the waste surfaces of the earth ; diatoms and confervas are 

 everywhere miraculously abundant in the waters, in rivers and 

 streams, in ditches and ponds, alike under the sunny skies of the 

 south and in the frozen regions of the north ; on the surface of the 

 sea in floating meadows, and in the dark and dismal recesses of 

 the ocean only to be explored by the long line of the sounding 

 lead. The ocean swarms with innumerable varieties, without their 

 presence being indicated by any discolouration of the water. The 

 Arctic and Antarctic Oceans covering areas larger than the 

 continents of Europe and Asia are peopled by myriads of 

 diatoms ; various inland seas and lakes are tinged of different hues 

 by their predominance in the waters ; while it has been ascertained 

 from the soundings obtained during the investigations connected 

 with laying the telegraph cable between "Ireland and Newfound- 

 land that the floor of the Atlantic is paved many feet deep with 

 their silicious shields, preserving in all their integrity their wonder- 

 ful shapes, notwithstanding the enormous pressure of the vast 

 body of water that rests above them, and the fact that they are as 

 tender and easily injured as the most delicate snowflakes. Such 

 is the wide space which these organisms occupy in the fields of 

 nature a prominence which is surely sufficient to redeem them 

 from the charge of insignificance. They are inferior in majesty 

 of form to palms and oaks ; but in their united influence it is not 

 too extravagant to say that they are not less important than the 

 great forests of the world. 



It may be asked by a class of persons, unfortunately too 

 numerous, what is the use of these humble plants ? In the 

 business language of the world things are called useful when they 

 promote the profit, convenience, or comfort of everyday life, and 

 useless when they do not promote, or when they hinder any of 

 these desired ends. But even judged by this standard Crypto- 

 gamic plants are not found wanting. Peat, so useful in many 

 places as fuel, is almost entirely composed of mosses ; while for 

 packing purposes and the preservation of plants growing in pots, 

 certain species of moss are very valuable. Lichens yield food to 

 man and beast j the Iceland moss constituting a large part of the; 

 diet of the people in the remoter parts of Iceland, and the rein- 

 deer moss forming the pasture fields of the reindeer in Lapland and 

 Greenland. As dye-stuffs, lichens are still employed, producing 

 under proper treatment some of the. most delicate and beautiful 



