122 SYSTEMATIC BOTANY. 



kormos, trunk), or plants with differentiation of stem and 

 leaves. It will be noticed that the old groups of Algse 

 and Fungi are abandoned in this classification, though the 

 two are physiologically quite distinct. The terms will be 

 frequently used ; Algse, denoting thallophytes with chloro- 

 phyll (and, therefore, assimilating inorganic matter) ; 

 and Fungi, thallophytes destitute of chlorophyll, and 

 hence parasitic or saprophytic. The first six groups are 

 sometimes called cryptogams {cryptogamia, Gr. kruptos, 

 hidden ; gamos, marriage, or union), or flowerless plants, 

 and they produce spores (destitute of an embryo) ; the last 

 group is called phenogams, or flowering plants, and 

 they produce seeds (having an embryo). 



PROTOPHYTA. 

 155. The lowest and simplest plants are included in the 

 r^ r^i^ r^ group Protophyta. They are often 

 [^ ( J M r^ exceedingly small, and can be seen only 

 I H M W ^''''^ ^^® ^'S^ powers of the microscope. 

 229 230 231 232 The nucleus has not been detected in 

 the cells of all of them, and some are destitue of a cell- 

 wall. The cells are either isolated or but loosely united 

 into families. The usual mode of multiplying is by fis- 

 sion ; that is, a cell, after attaining a certain size (Fig. 

 229), begins to constrict in the middle (Fig. 230), and this 

 continues (Fig. 231) till it is separated into two portions 

 (Fig. 232), each of which is a new cell. A modification of 

 the method of reproduction by fission is exhibited in the 

 so-called budding. On the adult cell (mother-cell) is pro- 

 duced a small cell (daughter-cell) which eventually becomes 

 separated (Fig. 235). Still another mode of reproduction 



Figs. 229-232. Successive stages in the process of multiplication by Fission. 



