82 FLOWERLESS PLANTS 



slender stalks, and the actual cases are black. 

 The spore case has arisen as the result of the 

 blending of the sex elements which are present 

 on the leafy growth of the liverwort, the actual 

 process being somewhat similar to that which 

 has been observed in the case of the mosses. 

 Of course, the spores which are scattered with 

 the ripening of the case give rise to the new 

 plant through the agency of a very incon- 

 spicuous growth [protonema). In nearlj^ all the 

 liverworts it is found that mingled with the 

 spores in the capsule are a number of spiral 

 bodies which have been called elaters. It is 

 probable that these bodies play some part 

 in assisting in the escape of the spores from 

 the capsule. A hverwort which is less abun- 

 dant in a wild state, but is often found in 

 greenhouses and on garden paths, is Marchantia. 

 In this case the male and female organs are 

 produced on little stalked devices which look 

 Uke miniature umbrellas. The spore cases arise 

 in groups on the underside of the female 

 branch. Apart from this method of reproduc- 

 tion Marchantia bears on its thallus special 

 brood bodies in cup-shaped vessels. These are 

 capable of giving rise to fresh plants when 



