Mosses and Lichens 



and green. They are common around the bases of ferns in the 

 woods and may be found in green-houses where ferns are propa- 

 gated. The pmthallium is the sexual or first generation in the 



life-history of a fern, for on it 

 are produced the antheridia 

 and archegonia necessary for 

 the production of the embryo 

 which shall grow into a fern 

 plant. 



It is not an easy matter to 

 keep clearly in mind the rela- 

 tion of the fern parts and the 

 leafy-moss parts. It will help 

 to do this, if one remember 

 that the criterion by which 

 the decision is to be made is 

 one of origin of parts rather 

 than of function and appear- 

 ance. A glance at the parallel columns will show that if one 



The alga scytonema growing with a fungus 

 to form the lichen Stereocaulon ramulosum. 

 Both alga and fungus consist of chains 

 of cells and belong to the group of Thallo- 

 {thytes. 



---..?r0thaUiu.wx ce.ll, 

 _C Ktorophijll, 



-cell, 



A vertical section of an 

 arche< ; onium ur female organ 

 t a i-rn- 



Hepatics with leafy stems. The leaves have no veins and are but one ceil thick. 



66 



