LYCOPODIAI.I-.S 



515 



are microsporangia, containing main* sin. ill mi< rospores. In form I 



sporangia arc alike; they differ in the number and size of their 

 contents. A mature microsporangium, with its subtending sporophyU 



and ligule, is shown in median section in Fig. 407. The line of deh 

 cence is distal, where the cells of the wall are smallest, and the 



Fig. 406. 



Selaginella inaequaii folia. A, fertile branch, half natural size. B, its tip in 

 longitudinal section, and enlarged, with microsporangia to the left, and D 

 sporangia to the right. (After Sachs.) 



structure of the cells of the wall is such as to lead to its valves being 

 everted as they dry on ripening, so that the spores are shed. The 

 mature megasporangium behaves in a similar way, but the spores arc 

 ejected forcibly by pressure of the everted valves upon them (Fig. 

 408). The spores fall upon the soil and germinate together. Thus 

 both the megaspores and microspores are shed from the parent plant. 



