Section 67. 



Section 68. 



CHAPTER NINE: THE NON-VASCULAR PLANTS 



Section 69. Introductory 360 



Section 70. The four great divisions ... ... 360 



Thallophytes : 



Section 71. Algae 362 



A. Unicellular forms .... 363 



B. Colonial forms 364 



C. Many-celled fresh-water forms . . . 365 



D. The groups of algaa . . 371 

 Section 72. Fungi 373 



A. Parasites and saprophytes . . 373 



B. Economic importance . 374 



C. Bacteria 374 



D. True fungi . ... 378 



E. Fungi and the soil . . . 391 



F. Lichens . 393 



Bryophytes : 



Section 73. Liverworts 395 



A. Reproduction 397 



B. Alternation of generations . . 401 



C. Leafy liverworts 403 



