280 HISTORY QF BRITISH MOSSES. 



germannia is manifested by the rapidity witli which the 

 plant withers, unless it is at once placed in the vasculum or 

 on paper after being gathered, rrom the same cause it 

 revives equally easily after being dry. In these cells will 

 frequently be found minute particles of different colours, 

 floating in a transparent fluid, which varies in different 

 species, and in different parts of the same plant, being green, 

 brown, purple, etc. , 



Taking in order the different parts of the plant, we find 

 that the 



Boots are primary and secondary ; the former being only 

 found in one or two J imgermannice ; the latter abundant, 

 and frequently very minute. In several species we find, as 

 in various Mosses, that roots originate from different parts 

 of the stem, leaves, and even of the fructification. An in- 

 stance of this occurs in Jungermannia co^iiplanaia, a com- 

 mon species. 



The Stem is cellular throughout, and in the more regular 

 branches of Jungermannia seems densest in the centre. It 

 varies much in appearance, being, as in the Marchantiacece 

 and frondose Jungermannia, mere flattened expansions, 

 more or less dense and elongated ; in one case minutely cut 

 into segments, like some Lichens or Alga, and in another 



