X CONTENTS. i 



CHAPTER III. 

 Morphology of the External Conformation of Plants. 



PAGE 



Sect. 20. Difference between Members and Organs. Metamorphosis . . .149 



21. Leaves and Leaf- forming Axes 153 



22. Hairs (Trichomes) 160 



23. The Root 162 



24. Different Origin of Equivalent Members 169 



25. Different Capacity for Development of the Members of a Branch-system . 176 



26. The Relative Positions of Lateral Members on a Common Axis . .187 



27. Directions of Growth 202 



28. Characteristic Forms of Leaves and Shoots 211 



29. Reproduction; Sexual Organs; Alternation of Generations . . .222 



BOOK 11. 

 SPECIAL MORPHOLOGY 



AND OUTLINES OF CLASSIFICATION. 



Group I. Thallophytes 231 



Class I. Protophyta 245 



„ 2. Zygosporeae 250 



„ 3. Oosporeae 267 



„ 4. Carposporeae 284 



Group II. MuscinesB 342 



Class 5. Hepaticae . . , 346 



„ 6. Musci 361 



Croup III. Vascular Cryptogams 385 



Class 7. Equisetineae 3^2 



„ 8. Filicineae 409 



„ 9. Dichotomeae ^60 



Group IV. Phanerogams ^36 



Class 10. Gymnosperms 4^8 



Sub-group. Angiosperms C34 



Class II. Monocotyledons 618 



„ 12. Dicotyledons 63, 



