126 PLANT-LIFE 



archegonia. A female plant with archegoniophores, 

 h, is shown in Plate IV., Fig. 6; it will be noted that the 

 disc of the archegoniophore is split into nine rays, or 

 arms. The female organs, archegonia, are flask-shaped 

 bodies, arranged in groups which are suspended in an 

 inverted position between the arms of the disc, and 

 surrounded by toothed sheaths; a sheath is technically 

 known as a " perichsetium." In the same plate, Fig. 10, 

 we see a section of an archegoniophore, showing, n, 

 pores leading to air-chambers; o, mucilage cells; p, ray; 

 r, archegonium with egg-cell in centre; and t, the peri- 

 chaetium. The mucilage secreted by the mucilage cells 

 diffuses some of its substance into the film of water, 

 which must be present if the sexual act is to take place ; 

 water supplied by rain or dew is sufficient. The sub- 

 stance diffused by the mucilage attracts the spermato- 

 zoids from a male plant; they swim to the archegonium, 

 enter at the opening of the neck, and traverse the canal 

 towards the egg-cell. Only one spermatozoid is per- 

 mitted to fuse with the egg-cell in the process of fertili- 

 zation. 



So far, we have outlined the story of the gameto- 

 phyte. With the fertilized egg-cell, which immediately 

 becomes an embryo, we enter upon an account of the 

 sporophy te, or asexual generation, consisting in this case, 

 when mature, of an oval sporogonium, or capsule, with 

 a stalked foot. Spores are developed in the capsule, 

 and among them are found curious elongated cells, called 

 " elaters." The elaters are hygroscopic; if we breathe 

 upon them, and in the meantime examine them under 

 a low power of the microscope, we shall see them make 

 some curious movements, occasioned by the moisture 



