LIVERWORTS A iVD MOSSES. 



53 



61. The origin of the leaves will be apparent upon com- 

 paring figures 64, 65, and 66. In Blasia ffig. 64) the thallus 

 is lobed, i.e., the edge has not grown equally, but continued 

 growing longer at certain 

 points. In Fossomlironia ( fig. 

 65) the flattened thalloid 

 form is still evident, but the 

 lobing has become so deep 



Fic 



Fig. 63. 



Fig. 62. — Gametophyte of Bazzania Xoz'^-HoUa^idicF. Besides the ordinary 



branches there are slender ones iflagella) with sparse minute leaves. Natural size. 



— .-\fter Lindenberg and Gottsche. 

 Fig. 63. — A^ dorsal \-ieTv; j9, ventral view of a piece of fig. 6a, magnified about 12 



diam., showing the stem, bearing two dorsal rows of large leaves and one ventral 



row of small ones. — -\fter Lindenberg and Gottsche, 



that the almost separate parts are usually called leaves. 

 In Xoteroclada (fig. 66) the central axis is still more com- 

 pact, and has lost its flat form, becoming a rounded stem 

 from whose flanks arise regular outgrowths, the leaves, each 

 of which corresponds to one of the lobes of the thallus in the 

 other forms. 



Mosses. 



In the mosses the complexity of the mature vegetative body 

 is somewhat greater. It is always developed as a shoot differ- 

 entiated into stem and leaves. 



62. Rhizoids. — The shoot is anchored, as in the liver- 



