700 



THE StJBDIVISIONS 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 difierent plants. The antheridia are 

 in the axils of the leaves of the male shoots, the archegonia 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. 897 —Mosses. 



» Polytrichnm commune; the spore-capsule to the left is concealed by the cap (calj-ptra). that to the right is exposed. 2 The 

 same moss iu an earlier stage of development. 3 Spore-capsule of Potytrichum cominune with its lid. * The same after 

 the falling away of the lid. * Brywm cee^piticium. * Spore-capsule of same with its calj-ptra. ' The same after remoral 

 of the calyptra. ^ The same after removal of the lid, showing the teeth (peristome). * X portion of the peristome, 

 enlarged, 10 Antheridia, archegonia, and paraphyses of Bryum axspiticium, »i Uylocomium spiendeiis. " Spore- 

 capsule of same. ^^ Andrecea rupestris with burst spore-capsule. ^* Sphatfuum eymbifolium; the spore-capsules are 

 still intact in the left-haod specimen. i& A single capsule of the same. 1. 3 &, 11, 14. natural size; >. ^ ^. ?. &. ^\ >', i& x5; 

 •. " X 160. 



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 I'esult, however, is achieved by a considerable 



