LIVERWORTS 



397 



The view of the inside of the body of the liverwort shows 

 that it is built a good deal on the plan of a green leaf. You 

 see the chloroplasts in the cells, more abundant on the 

 upper side. You see a pore in the epidermis which corre- 

 sponds in function to the stomate of a leaf ; it admits air 

 which diffuses freely in the air chamber beneath. In the 

 kind of liverwort 

 which is pictured 

 (Marchantia) the air 

 spaces are more 

 prominent than in the 

 leaf, and thin-walled 

 cells containing chlo- 

 rophyll grow up in a 

 peculiar manner from 



ir f fVi " 



the air 



chamber. The rela- 

 , i .!. 



tions between the air 

 and the thin-walled cells, however, are just the same as 

 in the leaf. The cells of the upper epidermis of this liver- 

 wort are waterproof, but the cells of the under epidermis 

 are permeable to water. 



A . Reproduction. Liverworts reproduce in three ways. 

 The simplest of these ways is by growing in front and dying 

 behind. Since liverworts have the habit of branching 

 frequently, you can see that this process results in the 

 formation of new individuals. You have noted the same 

 process in connection with the growth of underground stems 

 in seed plants. 



Another way of reproduction is by means of reproductive 

 buds which are often borne in little cup- or crescent-shaped 



' Two plants of Marchantia. The one 

 at the right bears arckegoniophores. The one at 

 the left bears antheridiophores. Each one bears 

 single cupide. See context. 



