LIFE HISTORIES 15 



manner. When the contents of the sporangium 

 are mature the wall of the capsule, and 

 especially the cells forming the annulus, begin 

 to lose water. The sides of the capsule start 

 to draw inwards, and ultimately the annulus 

 suddenly straightens out and the sporangium 

 is torn open, the actual rupture taking place 

 just at the base of the ring. 



The manner in which the spores originate 

 in the sporangium calls for comment. In the 

 case of the Male Fern these arise owing to 

 the repeated division of a single cell. At a 

 certain stage in the process there are produced 

 what are known as mother cells. Ultimately 

 these divide twice, and the resulting cells 

 represent the spores. When ripe, the spores 

 become kidney-shaped and the wall of the 

 cell takes on " a rich brown colour. In the 

 different kinds of Ferns, the form of the spore 

 and the sculpturing of its walls vary a great 

 deal. Thus the spores may be globular, oval, 

 or angular in shape ; whilst the exterior may 

 be quite plain, or, perhaps, most beautifully 

 marked. The number of spores produced in 

 the sporangium of a Male Fern is usually some 

 forty- eight to sixty-four, although in other 

 species there might be less than the lower 

 figure or more than the higher. To the naked 

 eye the spores appear to be so much dust, 

 and as they are comparatively light they 

 float away on the breezes, and often enough 

 travel for a considerable distance before coming 

 to rest. As a rule the bursting of the sporangia 

 takes place during dry weather. There is a 

 real advantage in this, for when the spores are 

 damp they hang together in masses and in 

 such a state a wide dispersal would be out of 

 the question. 



