526 



LIFE-HISTORIES 



by decay of the older part. Male gametangia (F) are borne on the 

 side of special branches which may be recognized as having their 

 leaves more crowded and often reddish (A and E). The numerous 

 male gametes (K) are more elongated and more spiral than those 

 of Marchantia, but are otherwise similar. Archegonia are produced 

 at the tip of short branches surrounded by comparatively large 

 leaves (Fig. 349, .4). After the female gamete has been fertilized, 

 the axis of the branch elongates into a stalk bearing at its tip the 

 enlarging sporophyte enveloped in the calyptra {B, C). The sporo- 

 phyte is differentiated into a short, thick foot {sg') and a capsule in 

 which there is a central mass of large air-filled cells surmounted by 



Fig. 350. — Cord-mos.-s {Funaria hygrornetrica, Cord-moss Family, [''unan'd- 

 cece). A, germinating spore {^\^) showing a sap-filled cavity or vaouolo 

 (v) a pseudo-root (w, w), and the old outer spore-wall (s). B, further 

 development of the thread (protonema) which comes from the spore, 

 showing the main thread {h) and side branches from one of which {h) 

 is growing a bud [K) destined to form a pseudo-stem and pseudo- 

 leaves, and already sending out a pseudo-root («')> ^i"- (Sachs.) 



a hollow dome-like mass of spores, and the whole inclosed in a firm 

 wall of small, hardened cells. A horizontal ring of these becomes 

 finally so brittle as to render the top of the capsule scparal^le like a 

 lid (C, d). As the capsule enlarges, the calyptra (c) is ruptured, and 

 as the spore-case dries its form changes perceptibly from spherical 

 to subcylindrical but without elongation. The result is that the 

 inner air-filled cells below the spore-mass are so much compressed, 

 that a degree of tension is soon reached sufficient to blow off the 

 lid with a perceptible report and scatter the spores to a distance of 

 several inches. Elaters are thus unnecessary. 



In Funaria (Figs. 350-356) the spores when germinating (Pig. 350) 

 produce a much-branched thread which mak(>s a bright green, felt- 

 like layer on moist earth. From this thread at many places arise 

 directly vertical pseudo-shoots each consisting of an axis bearing 



