ALTERNATION OF GENERATIONS IN MOSSES. 



47H 



ccdyptra, see figs. -'!-">o : ' and 350"). ultimately this hood is thrown off and the 

 capsule, within which quantities of spores are produced, opens. The spores are 

 readily distributed by the wind shaking the capsule cm its .stalk. It should be 

 noted that in Mosses this asexual generation (the sporogonium) never becomes 

 independent of the sexual Moss-plant; the base of its stalk always remains embedded 

 in the tissues of the sexual generation. In the Ferns, on the other hand, the 



Fig. 351.— Alternation of Generations in Mosses. Various forms of sporogonium, which as the asexual generation 

 have been produced at the tips of leafy shoots. 



1 Splachnum luteum. ■ An unripe capsule of the same. s A ripe and open capsule of the same. * Splachnum vasculomm 

 5 Longitudinal section of a ripe capsule of this Moss. 6 Splachnum ampullaceum. * An unripe capsule. a a ripe 

 capsule of the same. 9 and k> Schistogtega osmundacea. xl A ripe capsule uf the same. l , *. ,; . lu natural size- 2 , 3 x 2; 

 i.Ox 10; " x 15; 'xlOO. 



asexual ireneration ( = the Fern-plant), though at first drawing nutriment from the 

 ]ip 'thallium (cf. p. 475) by its "foot", soon becomes quite independent, the prothal- 

 lium dying away. The form of the sporogonium is very varied in different groups 

 of Mosses. In fig. 351 are shown the sporogonia of a number of Mosses, including 

 species of Splachnum (S. luteum, S. vasculosum, and 8. ampullaceum), a rare form 

 occurring on the excrements of cattle, reindeer, Szc, that of the already-mentioned 

 Luminous Moss (Schistostega osmundacea, cf. vol. i. p. 385); and in fig. 191, p. 16 



