— Plate 17. — 



Fig. I. — Aggregation in the stalk cells of Drosera rotitndifolia. These 

 photographs were provided by Dr. A. Akerman. A and B, successive 

 photographs of the same field taken 2 minutes apart; B and C, taken 

 15 minutes apart. 



Fig. 2. — Dionaea muscipula (Photograph by Dr. Cornelia M. Smith). 



Fig. 3. — Dionaea leaf which has captured a Harvest-man or Harvest- 

 spider {Phalangiiim sp). 



Fig. 4. — Drosera gigantea. This species grows to a height of four feet 

 (Western Australia). 



Fig. 5. — Aldrovanda vesiculosa (Silesia). On the right of the numeral 5, 

 half a whorl of eight leaves, axial view. 



Fig. 6. — Dionaea. Moving pictures taken at one-sixteenth of a second 

 intervals. The last one was taken half an hour later. 



E 



J 



