VI CONTENTS. 



CHAPTER IV. FECUNDATION; HETEROGAMETES. 



Sphaeroplea, ........ 79 



Fucaceae (Fucus, Halidrys), . .... 84 



Volvox, ........ 88 



CEdogonium, ... .... 89 



Coleochsete, ....... 91 



Vaucheria, ... ... 94 



Albugo (Cystopus), ... ... 96 



Achlya and Saprolegnia, . ... 102 



CHAPTER V. TYPE OF THE ASCOMYCETES AND RHODOPHYCE^E . 



Sphaerotheca, . 108 



Pyronema, 1 1 1 



Batrachospermum, . . 116-119 



Dudresnya, 119-126 



Collema, . 126-128 



CHAPTER VI. ARCHEGONIATES. 



Pteridophyta, -129 



The spermatozoid, . 130-136 



The egg-cell and fecundation, . . 136-142 



Gymnosperms, .... . 142 



Cycas, Zamia, and Ginkgo, 142 



The male gametophyte and the development of the sperma- 



tozoids, . . I4 2 -I55 



,The archegonium, . 156-158 



Fecundation, . . 158-163 



Pinus, 163 



The male and female gametoph) tes, . . . 163-164 



Fecundation, ...... 165-168 



CHAPTER VII. ANGIOSPERMS. 



The embryo-sac, or female gametophyte, .... 169-174 



The male gametophyte, 174-176 



The fusion of male and egg-nucleus, .... 176-177 



The fate of the second male nucleus in the eiabryo-buc, . 177-180 



Bibliography, ....... 181-187 



