MOSSES AND LIVERWORTS 83 



mature. The same kind of thing is to be noticed 

 in the species known as Lunularia vulgaris. 



The species of Hverwort which have been 

 noticed could never be mistaken for mosses, 

 but such is not the case with the foUaceous 

 kinds. The Tricholea has already been men- 

 tioned, but this plant is only one of a very large 

 number which bear a leafy stem. In many 

 of these liverworts the fohage is of a delicate 

 nature, which rapidly shrivels when brought 

 into a dry atmosphere. One very common 

 species is Radula complanata. This plant has a 

 small stem densely covered with leaves ; it 

 usually grows over tree trunks. In this case 

 the leaves, if examined, will be seen to be 

 divided into two lobes. The lower fold forms a 

 small pocket in which water is usually to be 

 found. The same kind of thing is to be observed 

 still more clearly in a very common tree-trunk 

 species {Frullania dilatata). Doubtless these 

 little vessels assist the plant in dry weather, 

 on account of the moisture which they contain. 

 Strangely enough, it is often found that minute 

 animals, such as the microscopic Rotifers, live 

 in the pockets of the Frullania. There is no 

 real evidence that the plant receives any bene- 



