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SPOROPHYTE OF BRYALES 



cup (Fig. 207, i). This is especially true of the antheridial 

 buds, the plants being monoecious or dioecious. The antheridia 

 and archegonia are essentially of the same structure as noted in 

 previous groups and they are usually associated with modified 

 leaves known as paraphyses (Figs. 207, 6; 208). The germina- 

 tion of the gametospore and the development of the sporophyte, 

 while presenting many features in common with the hepatics 

 and Anthoceros in particular, shows a remarkable series of varia- 

 tions that are of decided advantage to the .plant. The gameto- 

 spore in its early growth forms a spindle-shaped mass of cells, 

 the basal portion of which reaches down into the stem of the 

 moss plant and forms a well-developed absorbing organ or foot, 

 while the upper portion elongates by means of an apical cell 

 (Fig. 209, 10). Later, the growth becomes basal as in Antho- 

 ceros. For a time, the archegonium keeps pace with the elonga- 

 tion of the young sporophyte (Fig. 209, n), but finally it is 

 ruptured and lifted up as a cap, called the calyptra, on the apex 



FIG. 209. Germination of the gametospore : 10, base of the archegonium 

 in which the gametospore has germinated, forming a mass of cells with 

 apical growing cell, x. 11, later growth of the gametospore. The sporo- 

 phyte, spr, still enveloped by the archegonium, ar, appears as a cylindrical 

 mass of cells with foot, b, penetrating the stem of the moss plant. At 

 right an unfertilized archegonium. See Fig. 205, B. After Sachs. 



