282 ON BOTANICAL GEOGRAPHY. 



Caroline. So that in the vegetable, as well as in the 

 animal kingdom, the strong oppress the weak, and a con- 

 test takes place even among flowers, to all appearance 

 the symbols of peace and harmony. 



Mrs. B. I am sorry to spoil your poetical ideas of veg- 

 etation ; but such is the law of Nature. You will now 

 understand, that the richer the soil the greater is the num- 

 ber and variety of plants that can grow in it. Thus, in 

 tropical climates, the forests are composed of a much 

 greater variety of trees than in the temperate zone ; and, 

 as you approach towards the polar regions, the number 

 of different plants gradually diminishes. 



Emily. It is, perhaps, on this account that in the high- 

 lands of Scotland we meet with immense tracts where no 

 plant is to be seen growing but heath or furze. 



Mrs. B. Precisely. These species of plants being of 

 a hardy nature, and able to live in a soil from which most 

 other plants are excluded, meet with no competition, and 

 establish a colony apart from other plants. Such plants 

 are called by botanists Social, from their habits of living 

 together in societies. 



Caroline. I think they should rather have been called 

 unsocial, from their excluding plants of a different species. 



Mrs. B. They at least deserve the name of inhospita- 

 ble : the Potamogetons, which grow in stagnant waters, 

 Kelp wort (<Sa/so/a,) and Saltwort (Salicornia,) which grow 

 in salt districts, are of this description. There are some 

 plants which become social from their mode of propaga- 

 tion ; those, for instance, which have spreading roots, such 

 as the Hieracium Pilosella, or Mouse Ear Chickweed. 

 Plants, on the contrary, whose seeds are crowned with a 

 tuft, which enables the wind to have more power over 

 them, are dispersed to a great distance : between the^e 

 two extremes there exists a great variety of intermediate 

 degrees. 



There are some plants which, so far from excluding 

 those of a different species from their society, seem to take 

 delight in the neighborhood of trees to which they them- 



1521. What is said of the number and variety of plants that grow in 

 different climates'? 1522. In the highlands of Scotland what may be 

 found 1 ? 1523. Why do heath and furze grow there'? What are such 

 plants called^ 1524. Of this description what other plants are men- 

 tioned! 1525. What is mentioned of the Hieracium Pilosella; and 

 of plants whose seeds are covered with tuft'? 1526. What plants seem 

 inclined to grow in the neighborhood of trees to which they bear no re- 

 semblance 1 



