PAPERS ON BIOLOGY AND AGRICULTURE 77 



few hundred specimens from these countries exist in 

 American or European herbaria. To the taxonomist, 

 therefore, the latter countries mentioned, particularly 

 Nicaragua and Honduras, constitute an almost virgin 

 field for exploration and research. 



The natural 'conditions in Central America, namely, 

 the geographical formations, the varied topography, pre- 

 cipitation, air currents, trade winds, temperature factors, 

 etc., are such that the most pronounced changes in the 

 character of the vegetation are evident in contiguous 

 regions extending over relatively limited areas. Many 

 of these regions present to the ecologist interesting and 

 highly significant problems. This fact is shown con- 

 spicuously as one crosses the Republic of Costa Rica 

 from east to west, namely, from Port Limon on the 

 Caribbean Sea to Punta-Arenas on the Pacific. 



An adequate description of this country in few words 

 is beyond my ability to present. Briefly, however, the 

 east coast is low, the rain fall is abundant, and the vege- 

 tation is tropical. Cartago and San Jose are located on 

 an elevated plateau about 3000-3500 feet above sea level. 

 At least three rivers have their origin on this plateau. 

 To the north of San Jose and Cartago is the so-called 

 Cordillera Central, consisting of several volcanic moun- 

 tains, namely, Turrialba, Irazu, Barba, Poas, and others 

 ranging in elevation from 8000 to almost 12000 feet above 

 sea level. Immediately to the south of this plateau lies 

 the southern Cordillera with enormous mountain masses, 

 such as Buena Vista, Pic de la Vueltas, El Copey, and 

 Cerro de la Muerte (the wall of death), almost as high 

 as those peaks to the north. 



The general course of both Cordilleras is northwest 

 and southeast. The prevailing winds, at least during the 

 winter months, come from the east or southeast; there 

 is, therefore, an abundant precipitation on the eastern 

 and southeastern slopes of both Cordilleras. The coun- 

 try to the west of these great mountain masses, namely, 

 west of the continental divide, receives only a limited 

 amount of rain fall, especially during the winter months, 

 and the vegetation there is relatively sparse and presents 

 a marked contrast with that in the eastern part of the 



