398 THE NON-VASCULAR PLANTS 



structures called cupules. (See Figure 195.) The repro- 

 ductive buds which the cupules contain are called gemma. 

 Gemmae are bud-like bodies which become detached from 

 the parent plant and reproduce it. They occur in mosses 

 and in some pteridophytes as well as in liverworts. The 

 gemmae of common liverworts are green bodies a little 

 smaller than the head of a pin; they are plates of cells 

 which become detached from the short stalks on which 

 they are borne, and are carried away by the water which 

 often washes over the surface of the liverwort. 



The third way of reproduction in liverworts is much 

 more complex than the other two. Also it is the kind of 

 process from which the sex and seed reproductive habits 

 of the higher plants have been evolved. To understand 

 seeds it is important for you to understand the method of 

 reproduction about to be described. If it were not for seeds, 

 agriculture would be a very different thing from what it 

 is, and if agriculture were different, our lives would certainly 

 be different from what they are. So this process has a 

 real relation to your own life. 



Liverworts produce eggs and sperms. Plant eggs and 

 sperms are not new to you ; you learned of them in algae. 

 But in liverworts the egg is produced in a structure called 

 the archegonium. Archegonia you have not met before. 

 Neither algae nor fungi have them, but liverworts and 

 mosses, and all the fern plants bear their eggs in arche- 

 gonia. An archegonium is a flask-shaped structure which 

 bears an egg in its swollen base or venter. (See Figure 196.} 

 In Marchantia, which is that kind of liverwort shown in 

 Figure 195, the archegonia are borne on those structures 

 which bear finger-like branches at the top ; the archegonia 

 are found under the fingers, near their base; the necks 



