LIVERWORTS 



195 



(Fig. 358.) The upper surface of the disk shows openings scarcely 

 visible to the naked eye. However, a section of the disk, such as is 

 drawn in Fig. 361, shows that the pores lead into oblong cavities hi 

 the receptacle. From the base of each cavity there arises a thick 

 club-shaped body, the antheridium. Within the antheridium are 



361. Section through antheridiophore of marchantia, showing antheridia. 

 One antheridium more magnified. 



formed many sperm-cells which are capable of swirnming about in 

 water by means of long lashes or cilia attached to them. When the 

 antheridium is mature, its wall ruptures and allows the ciliated sperm- 

 cells to escape. 



The archegoniophores are also elevated on stalks. (Fig. 359.) In- 

 stead of a simple disk, the receptacle consists of nine or more finger- 

 like rays. Along the under side of the rays, between delicately fringed 

 curtains, peculiar flask-like bodies, or archegonia, are situated. The 

 archegonia are not visible to the naked eye. They can be studied only 

 with the microscope (x about 400). One of them much magnified is 

 represented in Fig. 362. Its principal parts are the long neck, a, and 

 the rounded center, b, inclosing a large free cell the egg-cell. 



We have seen that the antheridium at maturity discharges its 

 sperm-cells. These swim about in the water provided 

 by the dew and rain. Some of them finally, find their 

 way to the archegonia and egg-cells, which are thus 

 fertilized, as pollen fertilizes the ovules of higher plants. 



After fertilization the egg-cell 

 develops into the spore-capsule or 

 sporogonium. The mature spore- 

 capsules may be seen in Fig. 363. 

 They consist of an oval spore-case 

 on a short stalk, the base of which 

 is imbedded in the tissue of the re- 

 ceptacle from which it derives the 

 necessary nourishment for the de- 363 Archegoniophore 



with sporogoma of 



velopment of the sporogonium. At marchantia. 



Archego- 

 nium of mar- 

 chantia. 



