354 NOTES OF A BOTANIST CHAP. 



that of animals, I have been struck with the fact 

 that there are certain grand features of the vegeta- 

 tion which prevail throughout Cisandine America, 

 within the tropics, and even beyond the southern 

 tropic features independent of the actual distribu- 

 tion of the running waters, partly also of the geo- 

 logical constitution, and even of the climate to 

 which the range of the larger species of Mammals 

 and Birds corresponds in a considerable degree, but 

 not that of any other class or tribe of animals, and 

 especially not of lepidopterous Insects. These 

 features depend on the prevalence of certain groups, 

 or even of single species, of plants over vast areas: 

 one set prevailing in the Virgin or Great Forests 

 (Caa-guacu of the Brazilians, Monte Alto of the 

 Venezuelans) which clothe the fertile lands beyond 

 the reach of inundations, and constitute the great 

 mass of the vegetation ; another in the Low or 

 White Forests (Caa-tinga, Monte Bajo) --those 

 curious remnants of a still more ancient and 

 humbler but surpassingly interesting vegetation, 

 which (especially on the Rio Negro and Casiquiari) 

 are being gradually hemmed in and supplanted by 

 the sturdier growth of the Great Forests, wherein 

 they are interspersed like flower-beds in a shrub- 

 bery ; another in the Riparial Forests (Ygapii or 

 Gapo of the Brazilians, Rebalsa of the Spaniards), 

 on lowlands bordering the rivers, and laid under 

 water for several months in the year, where the 

 trees when young, and the bushes throughout their 

 existence, must have the curious property of being 

 able to survive complete and prolonged submersion, 

 constituting for them a species of hybernation ; a 

 fourth in the Recent Forests (Caa-puera, Rastrojo), 



