INSULAR FLORAS. 451 



peaks are very little more than 8500 feet above the level of 

 the sea. 



Baron estimated (19) the number of species of vascular 

 plants known as 4100; but Mr. J. G. Baker agrees with 

 me that we may now rightly raise this number to 5000 ; not 

 that they are all known in the sense of being published, for 

 many yet remain in herbaria undescribed. Nevertheless, 

 for the purposes of this article, Mr. Baron's figures and 

 other data will be used, supplemented by remarks on sub- 

 sequent discoveries of importance in geographical botany. 

 But these are few ; the additional novelties being chiefly 

 of no higher rank than species. 



Roughly speaking, the vegetation of Madagascar con- 

 sists of three zones, namely, the tropical plains, varying in 

 width, from the sea-coast inland; a belt of forest, encircling 

 the interior treeless zone, and also varying in width. Baron 

 reckoned the area of the forest-clad country at 30,000 

 square miles, or about one-eighth of the island ; but the 

 natives are destroying the forest in the most reckless 

 manner. He mentions, for instance, that no fewer than 

 25,000 trees were cut down to make a passage for a tomb- 

 stone that had been quarried in a certain place ! Should 

 this wanton waste be permitted to continue, many rare 

 plants will undoubtedly disappear. 



For purposes of comparison, I propose giving some 

 numbers and percentages for other countries, mainly from 

 tables of my own construction (1, 22, 23,) presuming that 

 in all cases they are merely approximations, though it may 

 be claimed for them that they are based upon fairly uniform 

 computations. 



Of the 202 l natural orders admitted by Bentham and 

 Hooker (24) 144 are represented in Madagascar. The 

 numbers in Central America (including Mexico), British 

 India and Australia are respectively 162, 174 and 154. 

 The number of natural orders of restricted distribution is 

 exceedingly limited, and Madagascar can only claim one 

 small group of plants, the Chlaenaceae, to which this status 



1 Baron erroneously places the number at 200. 



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