OF PLANTS. 255 



humus, with the greatest abundance and variety of plants. 

 Even in the north, the eye of the uninstructed observer is 

 struck by the greater richness and stronger development of 

 the vegetable kingdom, upon the argillaceous, basaltic 

 and porphyritic soils, and simple quartz sand is, under the 

 tropical sun, a desert, if water and therein foreign matters 

 be not furnished to it. 



DISTRIBUTION OF PLANTS UPON THE GLOBE WITHOUT 

 DEMONSTRABLE DEPENDANCE UPON PHYSICAL CON- 

 DITIONS. 



In the narratives introductory to the present Essay, I 

 have already noticed that Australia has, in common with 

 Europe, a very common plant, the Daisy. The same little 

 flower is found in northern Asia, in some regions in Africa 

 and South America, and where it occurs, it climbs the 

 mountains from the level of the sea up to the snow-limit. 

 The little Enchanter's Nightshade, the delicate Linnaea, the 

 Bitter-sweet, the Bird's Knotgrass, the blue Gentian, the 

 Dwarf Birch, and the Herbaceous Willow,* and several 

 others, are indigenous both in Europe and North America. 

 The common Self-heal, the Duckweed, and our Reed,f grow 

 in New Holland. The Bog-moss! covers the moors of 

 Peru and New Granada, as well as those of the Hartz, and 

 of Dovrefjeld in Norway. The brownish Parmelia which 

 clothes all our walls, palings and old trees, is no less 



* Circsea alpina, Linnsea borealis, Solanum dulcamara, Polygonum 

 aviculare, Gentiana Pneumonanthe, Betula nana, Salix herbacea. 

 f Prunella vulgaris, Lemna minor, Phragmites communis. 

 I Sphagnum palustre. 

 Parmelia subfusca. 



