an. 



Fig. 156. — Structure and development of the lloss-sporogonium (all figures, 

 except F, represent Fiinaria hygrometrica). A, Longitudinal section 

 through young capsule, apophysis (ap.), and the top of the stalk. 

 B, Part of the capsule in the region of the lid, much enlarged. C, Small 

 part of archesporium and spore sack, enlarged. D, Two pairs of 

 peristome-teeth (inner and outer). F, Aperture of dehisced capsule, 

 showing arrangement of peristome-teeth. F, Section of small part 

 of apophysis of Bryum argenteum. G, Single stoma, in surface view. 

 H and I, Stages in development of the sporogonium. a., archesporium ; 

 an., annulus ; c, calyptra ; Co., columella ; d., diaphragm ; ep., epi- 

 dermis ; /., foot ; i., inner peristome tooth ; I., lid ; «., neck of arche- 

 gonium ; 0., outer peristome tooth ; p., peristome-layer ; S., air-space. 

 (D after Ruhland ; F after Braithwaite ; F and G after Haberlandt ; 

 the remainder after Sachs.) 



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