XX 



CONTENTS 



CHAPTER XII 



THE CAUSES OF THE BUOYANCY OF SEEDS AND FRUITS OF LITTORAL PLANTS, 

 WITH ESPECIAL REFERENCE TO THOSE OF THE PACIFIC ISLANDS 



The classification of buoyant seeds and fruits.— The first group, where the cavity 

 of the seed or seedvessel is incompletely filled.— The second group, where 

 the kernel is buoyant.— The third group, where there is air-bearing tissue 

 in the seed-tests or fruit-coats.— The buoyant seeds and seedvessels of the 

 littoral plants of the British flora.— Summary Pages 104— 118 



CHAPTER XIII 



ADAPTATION AND SEED-BUOYANCY 



The question of the operation of Natural Selection.— Are there two principles 

 at work ?— The presence of buoyant tissue in the seed-tests and fruit-coats 

 of inland plants, both wild and cultivated.— Useless buoyancy.— The 

 buoyancy of seeds and fruits is not concerned with Adaptation.— Summary. 



Pages 119 — 129 



CHAPTER XIV 



THE RELATION BETWEEN LITTORAL AND INLAND PLANTS 



Professor Schimper's views.— Great antiquity of the mangrove-formation.— 

 Problem mainly concerned with the derivation of inland from littoral plants. 



Grouping of the genera possessing both coast and inland species. 



Scawola. — Morinda. — Calophyllum. — Colubrina. — Tacca. — Vigna. — 

 Premna Pa S es 130— 1 39 



CHAPTER XV 



THE RELATION BETWEEN LITTORAL AND INLAND PLANTS {continued) 



Inland species of a genus developed from littoral species originally brought by 

 the currents but no longer existing in the group.— Illustrated by the 

 Leguminous genera Erythrina, Canavalia, Mezoneuron, and Sophora, and 

 by the Apocynaceous genus Ochrosia.— The Hawaiian difficulty. 



Pages 140 — 154 



