INTRODUCTION 19 



The Island of Ometepe in Lake Nicaragua bears an 



active volcano. 



In regard to the geology it is only necessary to point 

 out a few of the more important characters. The high- 

 lands which hear so many active and quiescent vol- 

 canoes naturally show great masses of eruptive rocks, 

 some due to recent action and others much more 

 ancient. Porous tufa is a common material for sculp- 

 tures in many parts of Mexico and Central America. 

 In other places there are great beds of softer and finer 

 grained material also of volcanic origin. In these places, 

 such as Copan in western Honduras and Mitla in south- 

 ern Mexico, building in stone received its greatest 

 development. The soft greenish stone of Copan seems 

 to be a solidified mud flow permeated with volcanic 

 ash rather than a true lava flow of melted rock. Lime- 

 stones are also common and important in the economic 

 development. In some regions there are beds of a hard, 

 blue limestone going back to the Carboniferous epoch. 

 This -tone makes an excellent cement after burning. 

 The Peninsula of Yucatan is a great plain of limestone 

 of much more recent formation. Like our own Florida 

 it was once a coral reef which was lifted above the sea 

 by some natural agency. This limestone gets older and 

 more solid as we approach the base of the peninsula 

 but at best is rather porous and coarse-grained. 



The fauna and flora present great variation. In the 

 moist lowlands the monkeys play in the tree tops and 

 the jaguar lies in wait for its prey. Alligators and 

 crocodiles infest the rivers and swamp-. Two small 

 species of deer and the ocellated turkey are important 

 items in the meat supply of Yucatan, that includes also 

 the iguana, the peccary, and various large rodents. The 

 tapir and manatee are the large-t animals of the low- 

 lands but neither seems to have been of great signifi- 



