TRANSPIRATION AND LEAF- WATER 



TABLE II 

 The same. Piece No. 2 



Net loss: 0.2 cc. Weight of piece about 80 grams. 



within the intercellular passages is more difficult, and is, further, 

 not within the purview of the present paper. 4 



It is obvious that, if small differences in low rates of evaporation 

 from the leaf alone were to be determined in the ocotillo, the po- 

 tometer method would not be available. This is true also for any 

 short intervals during which little change in rate occurs. Large 

 changes during relatively short intervals, however, are registered 



4 See also Livingston, B. E. Cam. Inst. Wash., Publ. 50. 



