700 



THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. 



shoots at the apex of the plant (fig. 397 ^*); these shoots are respectively male and 

 female, and may occur on the same or on different plants. The antheridia are 

 in the axils of the leaves of the male shoots, the arehegonia in groups at the tips of 

 the female shoots. The fertilized egg-cell develops into the sporogonium, the lower 

 portion of which forms a large foot, whilst the upper part swells up into the spore- 



Fig. 397 —Mosses. 



> Polytrichum commune ; tlie spore-capsule to the left is concealed by the cap (calyptra), that to the right is exposed. " The 

 same moss in an earlier stage of development. 3 Spore-capsule of Polytrichum commune with its lid. * The same after 

 the falling away of the lid. s Bryum ccespiticium. « Spore-capsule of same with its calyptra. ? Tlie same after removal 

 of the calyptra. ^ x^e same after removal of the lid, showing the teeth (peristome). » A portion of the peristome, 

 enlarged, i" Antheridia, arehegonia, and paraphyses of Bryuin coespiticium. n Hylocomium, splendens. 12 Spore- 

 capsule of same. ^^ Andrecea rupestris with burst spore-capsule. '^^^ Sphagnum cymhifolium; the spore-capsules are 

 still intact in the left-hand specimen, is a single capsule of the same. 1. 2 s, 11, 14, natural size; 3. *. 6. ', 8, 12, is, 1= x5; 

 9, 10 X 150. 



capsule. The spore-layer in the latter has the form of a hemispherical shell. Ulti- 

 mately the archegonium is burst irregularly by the enlarging sporogonium, and the 

 spores are set free by the removal of a circular lid at the summit. 



In Sphagnum a true seta is not developed, the region between foot and capsule 

 remaining quite short. The same result, however, is achieved by a considerable 



