UNCLE IN ENGLAND. 129 



different continents is still less perceptible ; 

 there is scarcely any difference between those of 

 North America and those of the temperate regions 

 of the European continent. Between the two 

 temperate zones also the distinction is inconsi- 

 derable. Of thirty-six species from the Cape, 

 thirty occur in the northern hemisphere ; while 

 in other tribes of plants, Southern Africa has 

 many that are peculiar to itself. I may mention 

 poa as being one of the most extensively dis- 

 tributed genera ; some of its species are found 

 in every part of the world, from Spitsbergen to 

 New Holland." 



" We may say then," said Mary, " that 

 latitude has but little influence on these plants." 



" Yes, it has a decided influence/' said Miss 

 Perceval, " on their vegetation ; the tropical 

 grasses acquire a much greater height, and 

 almost assume the appearance of trees. Some 

 species of the bamboo, which you know belongs 

 to this tribe, are fifty feet high. The leaves too 

 are broader, and approach more in form to the 

 leaves of the other families of plants." 



I then asked Miss P. to give me some idea 

 of the distribution of those grasses which are 

 cultivated. 



(t The cultivated grasses," she said, " which 

 extend farthest to the north in Europe, are 

 barley and oats. These, which in milder climates 

 are not generally used for bread, afford the in- 



