128 BERTHA'S VISIT TO HER 



the earth; they are the principal support of 

 terrestrial animals ; and you know that the basis 

 of all agriculture is the cultivation of plants 

 which belong to their order." 



Miss P. easily allows herself to be drawn out, 

 and before we reached home, we obtained the 

 following particulars of that numerous family. 



" There are about eighteen hundred species 

 already known; and the industry of botanists 

 is every day adding to the list : there are both 

 land and fresh-water grasses, but no marine 

 grass. They occur in every soil ; generally in 

 society with other grasses, but sometimes a 

 single species will be found occupying a con- 

 siderable district. Sand appears the least favour- 

 able to their growth ; but even sand has species 

 peculiar to itself. They are spread over the 

 whole vegetable kingdom, from the equator to 

 the polar regions ; and from the sea-shores to 

 the tops of the highest mountains, at least to 

 the line of perpetual congelation. 



" We are still in want of a perfect natural 

 classification, by which their distribution on the 

 globe might be made more distinct : at present, 

 each of the ten groups into which they are 

 arranged, contains too many, so that not one of 

 the groups belongs exclusively to any one zone. 

 Some, however, may be regarded as tropical, 

 and some as chiefly inhabiting the temperate 

 climates. The variation of the grasses in the 



