VI CONTENTS. 



PAGE 



XXII. Hydrophytes 246 



XXIII. Adaptations to other plants as supports . 249 



XXIV. Symbiosis 252 



XXV. Animals as food, foes, or friends . . . 261 



XXVI. Protection and distribution of spores and 



seeds 270 



Appendix I. Directions for collecting and preserving ma- 

 terial 287 



II. Apparatus and reagents 293 



III. Outline of classification 297 



IV. Reference books 301 



Index 303 



