DEVELOPMENT OF PLANTS 



287 



while others, known as elaters, elongate greatly and serve to con- 

 duct the foods absorbed by the foot to the spore mother cells, and 

 finally they become spirally thickened (Fig. 194, C). These 

 elaters arise through the sterilization of certain of the spore- 



KIG. 194. Structure of the nearly mature sporophyte: A, continuation 

 of the growth in Fig. 193, C, showing the formation of a foot, /, stalk, and 

 capsules, c, which contain elongated dark cells, the elaters, and the spores, 

 The archegonium has been ruptured by the elongation of the stalk and is 

 not shown in the figure, p, perianth. B, enlargement of the base of A . 

 showing the attachment of the foot (indicated by darker lines) to the tissues 

 of the antheridial stalk. C, an elater and spores. 



FIG. 195. Archegonial branch with mature sporophytes: A, branch with 

 the dark capsules of several sporophytes projecting beyond the curtains of 

 the involucre. B, diagram of a branch as seen in section. On the right 

 one of the capsules of a sporophyte ruptured, exposing the elaters and spores- 

 On the left the curtain-like involucre only is shown. 



