CLASSIFICATION OF PLANTS 235 



larger, Family, Order, Class, and Phy'lum. In this way both the 

 plant and animal kingdoms are grouped into divisions, the smallest 

 of which contains individuals very much alike, and the largest of 

 which contains very many classes of individuals, each class hav- 

 ing some characters in common. This is called a system of 

 classification. 



Classification of Plants. — Four great divisions or phyla of the 

 plant kingdom are the Thal'lophytes or thallus plants, those which 

 have neither root, stem, or leaves ; the Bry'ophytes or mosses ; the 

 Pteridophytes (ter'i-d6-fits) or fern plants; and the Spermat'- 

 ophytes or seed-producing plants. Let us begin with the lowest 

 forms and briefly examine them, simply with an idea of knowing 

 how to distinguish them when we are out in the country or visiting 

 a park or a museum. Much pleasure, which is part of the purpose 

 of education, may be found in making collections, or at least in 

 being able to recognize the differences in the plant and animal 

 groups. The pages that follow are incorporated in this biology, 

 because the efficient citizen should be well informed along many 

 lines. This chapter may make us see the value of museums, bo- 

 tanical gardens, and zoological parks. 



I. The simplest plants, called Thallophytes (Lat. thallus, young branch ; Gr, 

 phyton, plant), have many forms. They may be single-celled, or many-celled. 

 They may or may not have chlorophyll, but they never possess the organs of 

 root, stem, and leaves found in the higher plants. Several groups are recog- 

 nized. These are the Bacteria, the Fungi, and the Algae. 



Bacteria are discussed in Chapter XXII. 



Tube fungus Sac fungus Basidium fungus 



Fungi. 



The Fungi are non-green plants of very great economic importance. There 

 are all together about 50,000 species known, and many are widely studied be- 

 cause of the harm they do. There are three groups or classes of fungi : 



