CBYPrOGAMS 169 



(fig. 345). Still less like Flowering Plants, Lut closely 

 iillied to the Ferns, stand the Mosses and Liverworts 

 (Figs. 340, 334). Jn the groups named — found at what 

 we speak uf as the upper end of the eryptoganuc series — 

 the stem-and-Ieaf type of structure prevails. In the lower 

 gi'oups a contrast in this respect will he noted. 



406. (ioing below the Liverworts — i.e. awa)' from the 

 Fhanerogams — we come to tiie Alg;e (Seaweeds and the 

 like, Figs. 291, 298), between vvduch and the Liverworts 

 the similaritjf is not marked. The Algte include all green 

 (chlorophyllous) plants below tlie Liver\^'orts, down to the 

 smallest and simplest (Fig. 282). Along with them, and 

 often resembling them in many respects, are the Fungi, of 

 which ordinary molds and toadstools are examples. Fungi 

 lack chlorophyll. 



407. In the Alg;e and Fungi the plant bo<ly is not 

 distinguished as in Flowering Plants and higher Crypto- 

 gams into axis or stem, and leaves. It is a simpler 

 structure, and is termed a tltallus. In the simplest 

 Cryptogams the thallus is the single cell constituting 

 the individual ; in higher forms it 1;iecomes a filament, 

 membrane, or solid mass. Alg;e and Fungi together are 

 termed Thallophytes. 



408. The Algaj fall into four grand divisions, conven- 

 iently distinguished in most cases by the color. In the 

 lowest group the green due to chlorophyll is more or less 

 modified by tlie presence of a blue pigment ; in the second 

 group the chloroph3dl gives its true hue ; in the third, 

 green is masked by brown ; and in the fourth, a red p)ig- 

 ment is usually present to obscure the green more or less 

 effectually. The description of typical Cryptogams will 

 begin with tlie simplest Algie. 



Throughout the present cha[iter merely the structures 

 and processes ntost commonhj found in the groups selected 

 will be described. Let it l)e understood that a full 

 account of even the few forms brought forward would 

 involve many f|ualifying additions to the general state- 

 ments now made. 



