54 



ductory matter is the statement (p. 8) that the "dominant vege- 

 tation of the Blue Mountains is, in accordance with the cUmate, 

 the evergreen broad-leaved forest, which is here of a type strongly 

 temperate in its fioristic make-up and in its vegetative character- 

 istics." Many will be surprised at such a characterization, and 

 not a few slow to accept. The list of species scarcely bears out 

 the statement that the floristic make-up is of a type " strongly 

 temperate." 



A very interesting section of the book is devoted to the relation 

 of physical conditions to habitat distinctions in the rain-forest 

 where the great difference between the forest floor condition and 

 that even a few feet in the air, is emphasized. To this is due the 

 well known layers of vegetation, particularly epiphytic, in tropical 

 forests. After a brief section on seasonal behavior of rain-forest 

 vegetation, and another on the rate of growth in rain-forest 

 plants, the author takes up the question of transpiration behavior 

 of rain-forest plants, which occupies nearly half the book. 



The author has sought to determine in this section of the book 

 (a) daily march of the rate of water loss, (b) effect of high humi- 

 dities and of darkness on the rate, (c) comparative amounts of 

 stomatal and cuticular transpiration in the slightly cuticularized 

 and thin-walled leaves of rain-forest plants, (d) the behavior of 

 stomata as affecting the rate of transpiration, (e) comparative 

 transpiration rate and transpiration behavior of different types 

 . . . simultaneously measured, and (b) the daily march of the 

 relative transpiration rate. 



An elaborate series of experiments were conducted to determine 

 these various points, and the book is a storehouse of figures and 

 graphs without number on such subjects. An interesting by- 

 product of this investigation is that the author was not able to 

 confirm the results of Lloyd, some years since, in which the 

 position was taken that the greatest transpiration is not synchro- 

 nous with the greatest opening of stomata. Shreve's graphs 

 show, on the whole, that when transpiration and evaporation 

 are highest the stomata aperture is largest. One very useful 

 result of the work is "the securing of simultaneous readings of 

 transpiration and evaporation which makes possible also the 



