314 



PLANT STUDIES 



gemmae fall off and develop new thallus bodies, making 

 rapid multiplication possible. Marchantia also possess re- 

 markably prominent gametophores, or " sexual branches " 

 as they are often called. In this case the gametophores are 

 differentiated, one bearing only antheridia (Fig. 285), and 

 known as the " antheridial branch," the other bearing only 

 archegonia (Figs. 286, 287), and known as the " archegonial 

 branch." The scalloped antheridial disk and the star- 

 shaped archegonial disk, each borne up by the stalk-like 

 gametophore, are seen in the illustrations. 



204. Jungermannia forms. — This is the greatest line of 

 the Liverworts, the forms being much more numerous than 

 in the other lines. They grow in damp places ; or in drier 



Fig. 288. Two liverworts, both Jungermannia forms: to the left is Blasia, which 

 retains the thallus forms but has lobed margins ; to the right is Scapania, with 

 distinct leaves and sporogonia (^4).— Goldberger. 



situations on rocks, ground, or tree-trunks ; or in the tropics 

 also on the leaves of forest plants. They are generally deli- 

 cate jDlants, and resemble small Mosses, many of them doubt- 

 less being commonly mistaken for Mosses (Fig. 288). 



In this line the thallus gradually passes into bodies 



