410 



BRYOPHYTES (MOSS PLANTS) 



is much more complex than the oogonium of the algae. In the 

 less lobed receptacles of the gametophores of the male plants (B, 

 Fig. 363) occur the antheridia, consisting of a stalk and of a jacket 

 of cells which encloses a mass of sperms as shown in Figure 366. 



B 



FIG. 365. Highly magnified vertical sections through the expanded tops 

 or receptacles of female gametophores of Marchantia, showing the sex organs 

 and sporophytes. A, section through female gametophore, showing the 

 archegonia (a), each of which consists of a neck and an expanded base called 

 venter, in which the egg (e) is located. B, section through a female gameto- 

 phore, showing sporophytes (s), with their sporangia (h), stalks (t), foot (/), 

 and also showing spores (i) escaping from the sporangium of the sporophyte 

 at the left. 



Since the sperms are produced on one plant and the eggs on an- 

 other, the sperms have a considerable distance to be carried to 

 the eggs. The sperms are splashed about during heavy rains, and, 

 when near an archegonium, they are attracted to the entrance in 

 the neck by an attractive substance which diffuses out of the 

 archegonium. The sperms swim down the canal in the neck of 

 the archegonium and the first one reaching the egg fertilizes it. 

 The fertilized egg or oospore remains where it was formed, be- 

 gins to grow and divide rapidly, and soon produces an oblong, 

 multicellular, brownish body which consists of a stalk that is 

 attached to the receptacle by an absorbing organ called foot 

 and bears at the other end a sporangium (B, Fig. 365). The 



