CELLULARES, OR CELLULAR PLANTS. 65 



more or less compact, and which is without any definite 

 figure. We are now about to enter on the examination of a 

 higher type of vegetation. 



HEPATIC^, OR LIVERWORTS. 



77. Plants composed of a distinct axis and foliage, and 

 which develop into root, stem, and leaves. — This distinction of 

 parts is first visible in the higher forms of the Hepatioae or 

 liverworts. The thallus, or vegetative part of the lower forms 

 of these plants, is a lobed and continuous mass of green vege- 

 table matter lying on the ground, and emitting root hairs 

 from every part of its under surface; but in the higher forms 

 of the Hepaticae the vegetative part is distinctly foliaceous, 

 although the organization of their minute leaves is of the 

 simplest character, which resemble in some species a two- 

 ranked series of imbricated scales, with an imperfect or rudi- 

 mentary row of leaves (amphigastria) on the under side. In 

 both kinds of Hepatioae, the reproductive matter is no longer 

 imbedded in the thallus or vegetative part; on the contrary, 

 it is contained in special and distinct organs. A capillary 

 peduncle, the type of a true stem, rises above the surface of 

 the frondose, soalelike vegetation, bearing on its summit a 

 valvular brown case or capsule, which contains the repro- 

 ductive matter or sporules. This capsule is without an oper- 

 culum or lid, and in most of the genera without a columella, 

 dehiscing at its apex, and opening by four spreading valves. 



78. Eig. 28 is an illustration of the workmanship which 

 nature exhibits in the formation of Jungermannia complanata, 

 a species which is common on the bark of trees in moist 



6* 



