indicated rates much lower than in tropical lowlands or in the 

 temperate regions, this being true even of the renewing foliage 

 of completely deciduous trees. A series of observations was 

 begun on the periodicity of growth, leafing-out, leaf- fall and 

 blooming, as well as on the duration of life of leaves in forest 

 trees and shrubs, but these observations require a longer con- 

 tinuous residence to be made of the fullest value. 



I made observations and did some experimental work with 

 regard to the significance of the wetting of leaves by rainfall and 

 condensed moisture. Dripping points are but poorly developed 

 in the native vegetation and the occurrence of epiphyceae was 

 found to be independent of the character of the foliage. The 

 wetting of the upper surface of leaves was found to reduce 

 transpiration, but both direct and indirect evidence showed this 

 to be due only in part to the cooling of the leaf. 



Many interesting features were revealed by a study of the 

 anatomy of the leaves of certain typical plants. 



A field study of the habitats and local distribution of the filmy 

 ferns was made, and supplemented by an investigation of their 

 moisture relations, particularly the capacity of roots and leaves 

 for water absorption, the capacity of leaves to avail themselves 

 of atmospheric humidity, and the behavior of chloroplasts in dry 

 and in strongly illuminated leaves. Material preserved for a 

 study of the anatomy of the leaves promises to show some inter- 

 esting structures securing mechanical stability in these thin 

 organs. 



Notes were taken for the preparation of a descriptive account 

 of the vegetation, with a particular view to correlating differences 

 in various habitats with the ascertained differences in physical 

 factors prevailing there. Differences in physiographic situation 

 were found to be at the bottom of the differences in physical 

 factors, and to be of more importance than altitude (above 4,500 



