Ch. 11] CHARACTERISTICS OF PLANTS 11 



group, which i~ much older, as shomi by fossil remains in 

 the rocks. 



2. The Fehxs and their kix, called scientificalh' Pteri- 

 DOPHYTEs or "Fern plants," comprise not only the familiar 

 true Ferns, but also the less prominent Horsetails and Club 

 flosses. They have no flowers, but reproduce by small one- 

 celled spores and a definite though not prominent sexual 

 ■stage. They live chiefly on land, have green leaves, and 

 make their o^\'ii food. They are mostly undergro'n-th plants, 

 though some in the tropics become trees. They have evolved 

 (it is likely but not certain; from the following group, and 

 were formerly more prominent than now, ha\'ing once formed 

 great forests, the earliest of such vegetation. 



.3. The ^Mosses axd their kix, called scientifically 

 Beyophttes or ''IMoss plants," comprise the true IMosses 

 with the Liverworts. They reproduce like the Pteridophytes, 

 by spores and a -exual stage. They have green leaves and 

 make their own food, but they rise little from the ground, 

 on which they grow densely together, thus forming the 

 simple.st carpet vegetation of the earth. They are de- 

 scended from the Alga, and were probably the fir.st plants 

 to cover the land. 



4. The ]\1olds axd their kix, called scientifically 

 Fungi, comprise a great number of small or minute plants 

 most of which are found associated with the disease and 

 decay of plants or of animals, e.g., mushrooms, yeasts, 

 molds, rots, rusts, mildews, and bacteria, — popularly kno^mi 

 as microbes or germs. Thej' occur in the most diverse situa- 

 tions, but always in contact either "nith li\'ing tissues, upon 

 which they live parasitically, or else -nith dead organic 

 substances, upon which they live saprophytically. The)' 

 are most diverse in forms, sizes, colors, and other features, 

 in accordance with their particular habits, but never show 

 the green color of the higher plants. They reproduce by 

 minute spores, which are carried everjTvhere by the T^inds, 

 thus explaining how those plants can occur in so many 



