EOOKS AND CURRENT LITERATURE 147 



roots was measured in trees growing in fresh and in salt water indicating 

 a more rapid rate in the former case. 



Biochemical work was done to test the relation between the amounts 

 of tannic acid and dextrose in the hypocotyl of seedlings at different 

 stages of growth after leaving the parent tree. No definite decrease 

 of tannin was discovered with the increasing amounts of dextrose, and 

 no evidence of the presence of tannase was secured. 



The field work carried out established the fact that the mangrove 

 reaches its optimum development in sea water, in spite of its facultative 

 behavior with respect to the salinity of its substratum. — Forrest 

 Shreve. 



