28 VEGETATION IN CENTRAL AMERICA. 



Page. 



Darwin, observation of climatic phenomenon in Brazil 16 



Denudation of land and rainfall 15-16 



areas now having desert vegetation 15-16 



suited to forests 21-22 



evidences 13-15 



Desert vegetation in denuded areas 15-16 



humid regions 19 



Deserts, artificial S-15 



induced by deforestation 23 



Drought on steep slopes 19 



Dry farming and dry season. See Farming, dry, and Season, dry. 



Earthenware, evidence of ancient civilization in Central America 17 



Egypt, comparison with Central America 9 



Epicampes, wire-grass 20 



Erosion affected by sheep grazing 12 



following deforestation 18-19 



prevention by terracing 10 



Farming, dry, use of terraces 18 



Fire, cause of permanent loss 11 



Firewood carried to towns 9 



Forests, botanical indications of recent origin 12-13 



burning 8 



denuded areas not naturally unsuitable 21 



in rocky and precipitous places 21-22 



kinds 12-13 



naturally continuous 22 



primeval 12 



replacing grass lands 11-12 



virgin, lacking : __ 12, 22 



Grass lands at different elevations i 7 



Grasses, extinction by forests 11-12 



occupation of cleared lands 11 



Grazing, effect on fires 11 



Guanacaste, Costa Rica, existence of oaks 19 



" Gumbo " soils 14 



Huehuetenango, Department 21 



Humidity decreased by deforestation 16 



Humus, arthropods inhabiting 13-15 



Insects inhabiting humus 13-15 



Introduction to bulletin 7-8 



Lake Yzabal, existence of pines 19 



Lands, alluvial, absence ' 9 



cleared, burning over 11-12 



occupation by grasses 11-12 



grass, at different elevations 7 



Maize culture, diverse systems 8-11 



Millipeds inhabiting humus 13-14 



Xenton region, corn culture 21 



Occupations, previous, shown by archaeological remains 16-17 



Ocosingo, ruins 14 



region, description 14 



Oaks at different elevations 7 



distribution determined by clearing of land 39-20 



in reforested areas 12 



145 



