MOSSES AND FERNS 



75 



entirely different kinds of gametes. In other words, 

 the moss described is hermaphroditic. 



d. The Sporophyte and the Formation of Spores. 



Evidently we now have a ferti- 

 lized egg. Judging from what we 

 have learned of animals, we might 

 expect this fertilized egg to es- 

 cape and to develop directly into 

 a new moss plant. But it does 

 not do this. It begins to divide 

 right where it is in the bottom 

 of the flask at the top of the up- 

 right stem. It develops a mass of 

 cells, known as a foot, that con- 

 nects it with the tissues of the 

 mother plant. Just above this is 

 a delicate stalk that may become 

 an inch or more long, called the 

 seta. At the top of this is a swol- 

 len portion, the capsule, in which 

 spores develop. All this develops 

 from the fertilized egg. The 

 whole structure is known as the 

 sporophyte, because its work is to 

 produce spores. It has no leaves 

 and gets the nourishment neces- 

 sary to grow and mature its 

 spores from the leafy moss plant 

 which is the gametophyte. (See 

 page 58.) Within the capsule 

 certain cells by their division pro- 

 duce numerous -spores; these final- 

 ly escape from the capsule and 

 the cycle is completed. We are 

 back to the point at which we 

 started, the spore that germinates. 



^m 



WcK^ 



Figure 20. Young 

 archegonium of 

 moss; much magni- 

 fied. From Coul- 

 ter s Plant Life and 

 Plant Uses. 



