252 The Plant World. 



which attain the same standard of excellence characteristic of 

 Professor Fink's work the time will not be far distant when a 

 really satisfactory North American lichen flora can be prepared, 

 Oakland, California. 



BOOKS AND CURRENT LITERATURE. 



Miyoshi, in the Journal of the College of Science of the Uni- 

 versity of Tokio, has published his "Botanische vStudien aus den 

 Tropen," based upon observations in Java, chieflv in the Botani- 

 cal Garden of Buitenzorg. The present paper deals with tropical 

 leaves in regard to form; size, and num.ber, texture, periodicity 

 of formation and other characteristics. Special attention was 

 given to the capacity of such leaves of becoming wet. The re- 

 sults as summarized by the author are as follows: 



(1) Trees and shrubs in Java and in other moist regions of 

 the Indo-Malayan tropics, in contrast with Japanese species, 

 possess for the most part leaves that are readily wetted on both 

 sides. 



(2) The capacity for wetting is to some extent dependent 

 on the age of the leaves. Many young leaves -which are not ca- 

 pable of being wetted become so later. 



(3) There are, however, numerous leaves which exhibit 

 this capacity when young as well as when they are old. 



(4) The capacity of tropical leaves of easily becoming wet 

 is not limited to plants of moist tropical regions. The leaves of 

 many trees in relatively dry tropical regions also possess this 

 characteristic. 



(5) The degree to which they are capable of becoming wet 

 does not depend upon leaf form. There are many leaves which 

 have no channelled tip which are nevertheless easily wetted. 



(6) It appears as if in some cases the capacity for becoming 

 wet is connected with the systematic position of the plant in hand. 

 Most of the Leguminosae, for example, which were investigated 

 by the author, though belonging in very different habitats, 

 have leaves either absolutely incapable of being wet or becoming 

 sO with difficulty. 



