THE BRYOPHYTA 141 



contact is a very close one there is never any organic 

 connection between the two generations. 



We see then that the sporophytic generation of 

 Funaria is in part parasitic on the sexual plant, in 

 part independent. It resembles in this respect a green 

 parasite such as the mistletoe, which, like the Funaria 

 fruit, must obtain all its water and mineral food from 

 the host-plant on which' it grows, but can provide its 

 carbonaceous food for itself. In some other Mosses, 

 however, the sporophyte is destitute of chlorophyll, 

 and so has to lead a completely parasitic existence, 

 depending for the whole of its food on the leafy Moss 

 plant. 



We will now return to the essential part of the 

 capsule, that, namely, in which the spores are 

 formed. The archesporium is at first only a single 

 layer of cells, and occupies but a small part of the 

 capsule (Fig. 63). Repeated divisions now take place, 

 and the archesporium increases in thickness. Ulti- 

 mately each of the cells formed by it becomes a spore 

 mother-cell, which, as is so usually the case, divides 

 into four spores, arranged tetrahedrally in each mother- 

 cell. As soon as the spores are ripe the capsule begins 

 to dry up. The columella and all the delicate tissues of 

 the fruit collapse, and when the capsule is fully ripe 

 it consists essentially of the wall only, filled with a 

 mass of dark-green spores. The lid becomes detached, 

 but the capsule after this is not left freely open, for 

 in the mean time a double row of teeth (called the 

 peristome) has been formed. These teeth, which project 

 from the edge of the capsule and partly close its mouth, 

 are formed from strips of thickened cell-wall, all other 

 parts of the cells involved having perished. The 



