LIVERWORTS OR HEPATICS 



HEPATIC/E 



Liverworts are as a rule found only in damp shady places, 

 and it is not their habit to occupy very large areas of ground. 

 With but few exceptions the plant lies close to the object upon 

 which it grows holding to it by short hair-like cells (rhiqoids). 



Excepting the fruiting portion, the liverwort plant (the vege- 

 tative body) is either ribbon-like (thalloid), or a stem with scale- 

 like leaves (f otiose)] the greater number of liverworts are 

 therefore distinguished as thalloid and foliose. 



RIBBON-LIKE OR THALLOID HEPATICS 

 Genus MARCHANTIA, (L.) 



Marchantia polymorpha (See Colour Plate XIII) is a good 

 example of a thalloid form, and from it one may learn, without 

 a microscope, the principal parts. 



Vertical section through 



Geixiixi& 



showing pore. 



a pore. Gemma. _ , 



Surface view 



Marchantia polymorpha 



The plant itself lies flat upon the earth and has a distinct 

 upper and lower tissue. 



The lower tissue develops short root-like hairs which serve 

 to anchor the plant. 



The upper tissue appears as if marked off into small rhom- 

 boidal spaces in tfc* centre of each of which a pore may be seen. 



93 



