280 REACTION OP THE INTERIOR OF THE EAETH 



work entitled, " Java, seine Grestalt und Pflanzendecke 

 und innere Bauart." Above 400 heights were measured 

 barometrically with great care ; the volcanic, conical, and 

 bell-shaped mountains, 45 in number, were all drawn in 

 profile, and, with the exception of three ( 405 ), were 

 all ascended by Junghuhn. Above half (at least 28) 

 were recognised as still burning and active; their 

 remarkable and very various forms have been most 

 clearly described, and the history of their eruptions, as 

 far as was possible, investigated. No less important 

 than the volcanic phsencmena of Java, are its sedimen- 

 tary rocks of tertiary formation, which previously to the 

 above-mentioned work were wholly unknown to us, 

 although they cover three fifths of the entire area of the 

 island, especially its southern portion. In many parts of 

 Java there are found, as remains of former extensive 

 forests, pieces, from three to seven feet long, of silicified 

 trunks of trees exclusively dicotyledonous. For a land in 

 which palms and tree ferns now grow in abundance, 

 this is the more remarkable, because in the miocene 

 tertiary rocks (the brown coal) of Europe, where arbo- 

 rescent monocotyledons do not now grow, fossil palms 

 are often found. ( 406 ) By diligently forming a collection 

 of impressions of leaves and of fossilised woods, Jung- 

 huhn has provided materials which, being ably examined 

 and worked up by Groppert into an " ancient flora " of 

 Java, have given us the first example of a fossil flora 

 from a purely tropical region. 



The volcanoes of Java are far inferior in height to those 

 which we have been speaking of in America, the Chilian, 

 Bolivian, and Peruvian groups, and even to the less lofty 

 groups of Quito and New Granada, and of tropical 

 Mexico (23,000, 21,000, and 18,000 feet), the highest 



