CHAPTER III. 

 LIVERWORTS (HEPATIC^) 



Habitat. Liverworts, which rank as the next higher group 

 above the Algse and Fungi, grow in streams and swamps and 

 on dry soil and trees. 



Morphology. The permanent plant body is always of 

 some shade of green because of the presence of chlorophyll. 

 In some, the plant body is a thallus, showing no conspicuous 

 differentiation into stem and leaves, but about nine-tenths 

 of the American species of liverworts have stem and leaves; 

 and some have a plant body that is transitional between a 

 thallus and a leafy stem. In Marchantia, a common thalloid 

 form of greenhouses and of burned places in the woods, the 

 upper surface is divided into diamond-shaped areas, in the 

 center of each of which is a pore communicating with an air- 

 chamber beneath. From the under surface of the thallus 

 grow tubular structures or rhizoids and plate-like masses of 

 tissue or lamells?. The rhizoids hold the plant in'the soil and 

 act as organs of absorption. The lamellae are rudimentary 

 leaves. 



Reproduction, In Marchantia and in some of the other 

 hepatics there are two forms of reproduction, (1) asexual 

 and (2) sexual. 



1. Asexual Reproduction is brought about by Gemmae or 

 Buds which in Marchantia grow on the upper surface of the 

 thallus in cup-shaped structures called gemmce cups. Each 

 gemma is a slightly constricted oval body attached to a stalk. 



