INTRODUCTION 7 



(2) Bryophytes. These are the first plants that in- 

 habited the land surface. The name means " moss-plants," 

 for the mosses are the most numerous representatives of the 

 group. 



(3) Pteridophytes. These are the first plants that de- 

 veloped a woody system. The name means " fern-plants," 

 for the ferns are the most numerous representatives of the 

 group. 



(4) Spermatophytes. This highest group developed 

 seeds, and the name means " seed-plants." Most of them 

 also developed flowers, and they are sometimes called 

 " flowering plants." It is the seed-plants that man uses 

 most, but to understand and explain them, one must know 

 the other groups. 



