xxvi CONTENTS 



CHAPTER XXXIII 



SEED-DISPERSAL AND GEOLOGICAL TIME 



The shifting of the source of Polynesian plants from the New to the Old 

 World. — The floral history of Polynesia stated in terms of geological time. — 

 The suspension of the agencies of dispersal in later periods. — Parallel 

 differentiation in the course of ages of climate, bird, and plant. — New 

 Zealand. — Insects and bats as agents in plant-dispersal. — The effective 

 agency of sea-birds in other regions. — The observations of Ekstam. — The 

 Spitzbergen controversy. — The efficacy of ducks as distributors of aquatic 

 plants. — Summary . . Pages 502 — 514 



CHAPTER XXXIV 

 General Argument and Conclusion . Pages 515 — 523 



APPENDIX . Pages 525—605 



