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THE AM ERIC AX XATURALIST [Vol. XLVI 



and much of this is so elevated that the Mora is not really a 

 tropical one. The whole of the interior of Mexico is an elevated 

 tableland, with a flora closely resembling that of the southern 

 and southwestern United States. 



The eastern coast of Mexico, together with Central America 

 and Panama, possesses a tropical flora belonging with that of 

 South America. In this region Palms, Aroids, Cannacea?, Bom- 

 bacaeeas, arborescent Leguminosae, and other tropical types 

 abound, and there is a very rich development of epiphytic 

 Orchids and Bromeliads. 



The extreme southern part of Florida, as we have seen, is the 

 only part of the United States which properly belongs to this 

 tropical area, although a good many Southern types extend 

 much farther north than this. Such Southern types are the 

 Palmettos, Tillandsia, and other Gulf-state species. 



While the eastern coast of Mexico has a humid hot climate with 

 the typical tropical flora, the western coast is extremely arid 

 with a scanty xerophytic vegetation. 



The West Indian region is treated by Dr. Harshberger as a 

 distinct province. There is developed here a rich and interesting- 

 flora, allied, as might be expected, to that of the American main- 

 land, but comprising many peculiar species. The larger islands 

 are very mountainous and great differences in the vegetation 

 conditioned by topography may occur within very short dis- 

 tances. This is well illustrated in Jamaica, where the vegeta- 

 tion on the north and south sides of the island is very different, 

 although only forty miles apart. This difference is caused by 

 the presence of a range of mountains over seven thousand feet 

 high in the middle of the island. Jamaica is remarkable for the 

 great development of Ferns, being perhaps the richest area of 

 its size in the world. It is said that some five hundred species 

 occur in the island, which has an area of only about four thou- 



Dr. Harshberger \s handsome volume is illustrated with a pro- 

 fusion of excellent figures, many of them original photographs, 

 which add greatly to the value of the book, which must remain 

 for a long time to come the standard work on the distribution of 

 the plants of North America. 



Douglas Houghton Campbell 



Stanford University, 

 December, 1911 



