42. 

 View that the evaporation , or to te more exact, the 

 evaporating power of the air is prohahly the most 

 important factor in the distribution of the epiphQrte,'^ 

 The total aver^ea for evaporation both on the juniper 

 and on the oak are shown in the graph (Fig, 3.3) and the 

 daily averages of evaporation, light intensity, air 

 temperature, substratum temperature, and the relative 

 humidity of the air for each height and exposure on 

 the trtmk of the tree, with the corresponding epiphytic 

 flora, are tabmlated in Table II, These readings are 

 given for each period during which records were obtained. 

 In Table III are given thdtotal averages for all the 

 periods for each individual station on both the juniper 

 and the oak which are arranged in the order of the 

 la te of evaporation, beginning with the station that 

 has the least evaporation rate and ending with that 

 showing the maximum rate.The corresponding epiphytic 

 flora for each station and the total averQaes of the 

 other factors are also presented in the table so thAt 

 it is possible to see at a glance the relation of 

 the occurrence of the epiphyte to the climatic 

 conditions, It appears from the tabulated results 

 that where the evaporation rate is low, the epiphytic 

 fern is present and where the evaporation is hi^ the 

 polypody is wanting. When these readings are presented 

 graphically the fact becomes even more obvious, as is 

 shown by the graph (Fig, 14), that the epiphytic flora 



