CONTENTS XI 



PAOB 



CHAPTER VIII. THE MORPHOLOGY AND PHYSIOLOGY OF SEEDS . 372 



1. The distinctive characteristics of seeds .... 372 



2. The structure, morphology, and functions of seeds . . 373 

 3. The suspension of vitality, resting period, and duration 



of life in seeds . 377 



4. The germination of seeds 381 



5. The economics and cultivation of seeds .... 385 



6. The cycle of development from seed to seed , 386 



PART II 



THE KINDS AND RELATIONSHIPS OF PLANTS 



CHAPTER IX. THE PHYLOGENETIC CLASSIFICATION OF PLANTS . 391 



CHAPTER X. DIVISION 1. THALLOPHYTA : THE THALLUS PLANTS 396 



Class 1. Cyaiiophycese : the Blue-Green Algae .... 399 



Class 2. Schizomycetes : the Bacteria 402 



Class 3. Flagellata : the Flagellates . . . . . . 410 



Class 4. Myxomycetes : the Slime Molds . . . . .412 



Class 5. Chlorophyceae : the Green Algae 415 



Order 1. Protococcales : the Unicellular Green Algae . 416 



Order 2. Confervales : the Confervoid Algae . . . 420 



Order 3. Conjugates : the Conjugating Algae . . . 424 



Order 4. Siphonales : the Tubular Algae . . . . 429 



Order 5. Charales : the Stoneworts . . . . . 432 

 Class 6. Phycomycetes : the Algal Fungi . . . . .434 



Order 1. Saprolegniales : the Water Molds ... 435 



Order 2. Peronosporales : the Blights .... 436 



Order 3. Mucorales : the True Molds 437 



Class 7. Phseophyceae : the Brown Algae ..... 439 



Order 1. Phaeosporales : the Kelps 440 



Order 2. Fucales : the Rock weeds 442 



Class 8. Rhodophyceae : the Red Algae 443 



Class 9. Ascomycetes : the Sac Fungi 447 



Order 1. Discomycetes*: the Cup Fungi .... 450 



Order 2. Pyrenomycetes : the Black Fungi . . . 452 



Order 3. Erysipheae : the Powdery Mildews . . . 455 



Order 4. Plectascales : the Blue and Green Molds . . 456 



Order 6. Exoasci : the Naked-ascus Fungi . . . 458 



Order 6. Saccharomycetes : the Yeasts .... 458 



Order 7. Lichenes : the Lichens . ... 459 



