GEOGRAPHICAL DISTRIBUTION. 11 



or more. From China, also, there have been a 

 few introduced to our country ; where in the 

 southern provinces the heat is greater even than 

 in Bengal. 



PART III. AFRICA. 



Africa extends in length from the Cape of 

 Good Hope to the Mediterranean, on the coast of 

 Tunis ; its greatest breadth is from Cape Verde 

 to Cape Guere-a-fiu, forming a vast peninsula, se- 

 parated from Europe by the Mediterranean, and 

 from Asia by the Isthmus of Suez and the Red 

 Sea, and holds the third rank, in regard to size, 

 of the four quarters of the globe. But the dis- 

 tribution of Orchideae over the greater portion of 

 the country is extremely meagre, indeed, through- 

 out the northern and most of the eastern parts, 

 together with much of the interior vegetation in 

 general, is very scanty, which is attributable to the 

 excessive heat and long-continued droughts this 

 part of the world is subject to, so torrid as to 

 render a great portion entirely desert. 



But on the other hand, in the south-western 

 parts of Africa, where the soil and climate are 

 congenial, its flora is rich in a corresponding 

 degree, particularly in Sierra Leone, the humid 

 atmosphere being so very great as to be inimi- 



