174 A TEXT-BOOK OF BOTANY 



in addition to absorbing food from the thallus through the 

 bulbous base. In the other liverworts the sporophyte is 

 entirely dependent upon the gametophyte for its food; 

 but in the Anthoceros forms the sporophyte, by developing 

 green tissue, has begun to be somewhat independent. 



Another important feature of the sporophyte of this 

 group is that it continues to increase in length like a stem, 

 but the growth takes place at the bottom of the spore-case. 

 As the pod-like spore-case splits into two valves, beginning 

 at the top, the ripe spores above are first exposed and scat- 

 tered; as the splitting becomes deeper the region of the 

 younger spores is reached; and so on until the capsule has 

 become completely split, and all the spores have been ex- 

 posed (Fig. 169, B). 



It is evident that the Anthoceros forms have the most 

 complex sporophytes among liverworts. In addition to 

 producing spores, these sporophytes have a bulbous absorb- 

 ing base and develop green tissue for the manufacture of 

 food. 



