x CONTENTS 



Type V 



PAGE 



THE MALE FERN (Aspidium Filix-Mas) . . . .37 



I. External Characters 



A. Vegetative Organs ..... 38 



B. Reproductive Organs ... 42 



II. Internal Structure of the Sporophyte 



A. The Vegetative Organs 



1. The Stem 



a. The Vascular System . .44 



/3. Other Tissues of the Stem . 48 



2. The Leaf . ... 48 



3. The Root ...... 50 



4. The Growing-Points 



a. The Stem ..... 52 

 p. The Root ..... 53 

 7. The Leaf . . . . .55 



B. Reproductive Organs of the Sporophyte . . 55 



III. The Oophyte or Sexual Generation 



A, Development and Structure of the Prothallus . 61 



B. Development and Structure of the Sexual Organs 



1. The Antheridia 65 



2. The Archegonia ..... 67 

 0. Fertilisation . . . . . .69 



D. Embryology ...... 71 



E. Comparison between the Life- History of Ferns and 



that of the Higher Plants ... 73 



Type VI 



THE FIELD HORSETAIL (Equisetum arvense) . . .78 

 I. External Characters of the Sporophyte 



A. Vegetative Organs . . , . .80 



B. Reproductive Organs . . . . .82 



