TERTIARY FLORA OF CHILE 109 



1. near Tumbez, Peru. 



2. Lota and Tablayacu, Ecuador. 



3. Cauca Valley, Colombia. 



a-a. Present southern limit of palms. 



b-b. Approximate western and southern limits of Zamia, Iriartea, 



Bactris, Euterpe, Chamadorea and Triplaris. 



c-c. Approximate western and southern limits of Podocarpus, 

 tree ferns, Myricaceae, Proteaceae, Cunoniaceae, Coriariaceae, 

 Melastomatacese, Lauraceae, Myrtaceae, Guttiferae, Sapo- 

 taceae, etc. 



The small scale of the map and the absence of detailed informa- 

 tion over large areas renders these lines very inexact, but sufficient 

 to bring out certain general relations, which is all that is intended. 

 The probable outline of the southern coasts if the present sea- 

 bottom were raised to the 550 fathom line is shown. The major 

 part of this submerged area is within the 100 fathom line. 



factor, and recent experiments have shown that many plants 

 will not seed under conditions of abnormally continued light- 

 ing. Again the amount of precipitation is within certain 

 limits less important than its seasonal distribution. This is 

 the main reason our own western prairies are treeless. 



We may have in the equatorial zone every stage of transi- 

 tion from evergreen rain forest through monsoon forests, 

 savanna, thorn forest, bush, grassland to desert, in response 

 to the gradually diminishing amount of rainfall during the 

 wet season. 



It seems obvious in the case of the Chilean Miocene flora 

 that the prevailing winds were, as at present, from the 

 Pacific, hence there is little question regarding the abundant 

 precipitation at that time and if the fossil plants failed to 

 show this the sediments would, for they indicate an abun- 

 dant run off. 



The remaining question is one of altitude and temperature. 

 Obviously the coal beds were deposited near sea level the 

 intercalation of marine beds indicates this. Certain of the 

 seams have every appearance of having had an allocthonous 



