NATURAL AREAS AND REGIONS 



617 



Panama Canal. This gigantic under- 

 taking, involving the destruction of 

 formerly unbroken forest and the crea- 

 tion of Gatun Lake, approximately 164 

 sq. mi. in area, along a transcontinental 

 belt has had a profound effect on the 

 local fauna and flora. Species re- 

 stricted to the original forest interior 

 are replaced by those of widely different 

 associations which thrive on forest 

 borders or in cleared spaces where 

 grasses, herbaceous vegetation, and a 

 multitude of shrubs and vines of low 

 growth are the first to secure a foothold. 

 In these cleared spaces many birds and 

 certain mammals such as the cotton rats 

 rice rats, and white-tailed deer not 

 found in the depths of the forest find a 

 congenial environment. Along the for- 

 est borders marking the edges of the 

 clearings, on the other hand, some for- 

 est mammals, especially ground-inhab- 

 iting rodents, increase in number 

 owing to the more abundant food sup- 

 plied by the low growing vegetation. 



The impounding of the waters of the 

 Chagres River to form Gatun Lake in 

 an interior basin, and the diversion in 

 this way of Atlantic drainage to the 

 Pacific through the canal has brought 

 about marked changes in water relations 

 on the Isthmus. The rising waters 

 of Gatun Lake destroyed the forest 

 and permitted the extension of many 

 aquatic species into a new area where 

 the development of stable associational 

 relations may be expected to require 

 considerable time. The white-tailed 

 deer (Odocoileus chiriquensis), seems 

 to be absent in the depths of the un- 

 broken forest where it is replaced by 

 the forest deer (Mazama sartorii reper- 

 ticia), but favors the forest borders 

 or the dense thickets and mixed growth 

 of small trees and shrubby vegetation 

 which have sprung up in the partly 

 cleared spaces. From the partly open 

 country near the Pacific coast of the 

 Isthmus it appears to have followed the 

 Canal route northward nearly to Colon. 



Along the southern side of Panama 

 settlements occur at intervals in the 

 savanna and arid deciduous forest type 



of country and stock raising is carried 

 on to a rather limited extent. On the 

 southern slopes of the lofty Volcan de 

 Chiriqui in western Panama some forest 

 has been cleared and the land devoted 

 to the growing of coffee and other crops. 

 In the vicinity of Bocas del Toro in the 

 northwestern part of the Republic 

 formerly forested areas near the coast 

 have become the seat of a banana- 

 growing industry. 



Considerable sections of the mixed 

 savanna and arid deciduous forest 

 extending along the Pacific coast from 

 the Costa Rican frontier east to the 

 Rio Chepo are swept annually during 

 the dry season by fires which tend to 

 limit the extension of forest growth. 



III. ACCESSIBILITY OF NATURAL 



AREAS (E.A. G.) 



The regular steamship routes con- 

 verge to the Atlantic and Pacific ports 

 at the ends of the Panama Canal. From 

 these ports or stations on the Panama 

 Railroad many points in the vicinity 

 of the Canal Zone embracing a variety 

 of local conditions are easily reached. 

 Barro Island in Gatun Lake has recently 

 been made a station for tropical re- 

 search by various institutions, and this 

 or other points in the Canal Zone may 

 conveniently be used as headquarters 

 for field operations in many parts of 

 Panama. 



Some of the steamers to and from 

 Colon to Port Limon make stops at 

 Bocos del Toro. Small vessels make 

 trips coastwise from Panama, at the 

 Pacific end of the canal west to David 

 from which transportation may be 

 secured to the elevated region about 

 the Volcan de Chiriqui. Small vessels 

 or motor boats also make trips from 

 Panama to the Pearl Islands, to Chepo 

 on the Rio Chepo and to points as far 

 east as Real de Santa Maria near the 

 head of motor navigation on the Rio 

 Tuyra. The Atlantic coast from Porto- 

 bello eastward is practically uninhabited 

 except by Indians and access to that 

 section is difficult. Although the Isth- 

 mian region is narrow the greater part, 



