CHAPTER lY. 



CENTRAL AMERICA (GUATEMALA, HONDURAS, SAN SALVADOR, NICARAGUA, 



COSTA RICA). 



I. — General Survey. 



HE long strip of tropical lands disposed in the direction from north- 

 west to south-east between the Tehuantepec Isthmus and the Atrato 

 valley, constitutes a geographical region quite distinct from the 

 great continental masses of North and South America ; they are, 

 however, usually grouped with the northern section of the New 

 AVorld, to which they are attached by a broad base gradually narrowing south- 

 wards. In a remote geological epoch they were detached from both, constituting 

 a chain of islands analogous to those of the West Indies. But the exploration of 

 these lands is still far from complete, except in a few districts separated from each 

 other by less-known intervening tracts ; hence it is not yet possible to indicate the 

 exact outlines of this insular chain before the marine channels were filled up. It 

 seems evident, however, that this process was not accomplished in a single epoch, 

 and some of the passages still persisted for long ages after others had been changed 

 to dry land either by eruptive formations or by alluvial deposits. 



Some of the ancient interoceanic channels, such as those of Tehuantepec and 

 Nicaragua, may still be clearly traced along their primitive shores. The Costa 

 Eica and Panama peninsulas are also now attached to the mainland by isthmuses 

 whose original marine character is easily determined. The other straits are more 

 difficult to recognise ; but it is no longer doubtful that the sea formerly occupied 

 the central depression of Honduras at the Guajoca and Rancho Chiquito passes, 

 as well as the central plateau of Costa Rica, at that of Ochomogo. Other channels 

 flowed between Chiriqui and David Bays, while the track of the Panama and 

 Darien Canals was already indicated by the former marine depressions, one of 

 which is also now occupied by the valley of the lower Atrato. The narrowest part 

 of these isthmuses has been attributed politically to the South American State of 

 Colombia ; but such official awards correspond in no way with the divisions f;ir 

 more sharply traced by the hand of nature herself. Thus the physical limit of 

 Central America is still clearly determined in Colombian territory by the course 

 of the Atrato, the wooded morasses lining its banks and the depression connecting 

 this fluvial basin with that of the San Juan. 



