CAPSULES 



The capsule of a moss is often spoken of as the 

 '* fruit." It is the swollen case containing the spores at 

 the end of a slender stalk called the seta, or partly hid- 

 den_by the surrounding leaves, and develops, like all 

 fruit, after the flower has been fertilized. (Plate IV, 

 Fig. I.) 



Great care must be taken when studying the cap- 

 sule to be sure it is old enough to show the typical form 

 and position. A young capsule is nearly always pale 

 green and very slender, shrinking a good deal when 

 dry. A capsule is mature when the spores are ripe and 

 ready to be scattered, and it is then yellowish- or red- 

 dish-brown, well filled out, and does not wholly lose 

 its characteristic shape in drying. Sometimes a green 

 capsule is sufficiently developed to show the typical 

 form, but it must be at least filled out if not beginning 

 to change color. When the spores have all been scat- 

 tered, the capsule is spoken of as empty, but in many 

 cases it retains its characteristic shape for some time. 

 Often both old and young capsules may be found at 

 the same time. Extremes in either case should not be 

 used for study, as a very old capsule becomes dark and 

 decayed or broken, or, if at first erect, it may become 

 bent over. Most mosses mature their spores in the fall 

 or early winter, the rest do so in the spring or summer. 



