TABLE OF CONTENTS. 



INTRODUCTION. 



PAGE 



Books relating to British Freshwater Algae 1 



Occurrence, collection, and preservation of Freshwater Algae . . 3 



Cultivation of Algae 9 



ALG.E. 



Algae : what they are, and the six classes into which they are divided 10 



Structure of Freshwater Algae 11 



Vegetative multiplication 13 



Asexual reproduction 14 



Sexual reproduction 15 



Polymorphism ........... 18 



Phylogeny and classification 21 



Class 1. RHODOPHYCE^E, p. 34. 



Order I. NEMALIONACE^ 36 



Family 1. Helminthocladieae 36 



Batrachospermum, Chautransia, Thorea 



Family 2. Lemaneaceae 40 



Lemanea, Sacheria 



Order II. CRYPTONEMIACE^ 43 



Family 1. Squamariaceae 43 



Hildenbrandtia 



