68 BIOLOGY GENERAL AND MEDICAL 



FIG. 16. Sundew (Drosera rotundifolia) . Each leaf is covered with tentacles 

 whose function is to catch the insects upon which the plant preys. Each ten- 

 tacle is covered with a sticky secretion which detains the victim until neighbor- 

 ing tentacles are able to curve over it and completely invest it. The insect is 

 then smothered, and digested by enzymic secretions, its substance aiding the 

 nutrition of the plant. (From Bergen and Davis's " Principles of Botany," 

 Ginn & Co., publishers.) 



