V. MOSSES (MUSCI): SPHAGNALES—ANDRE^ALES \77 



detached. Schimper states that antheridia may be formed at 

 any time, but they are more abundant in the late autumn and 

 winter. 



The archegonia are found at the apex of some of the short 



'>^^\yU}^ 



Fig. 92. — Sphagnum acutifoUum. Development of the embryo (after Waldner). A-D, 

 Median optical section; E, F, cross-sections. A, D, E, F, X360; C, X315; D, 

 X153. 



branches at the summit of the plant, which externally are indis- 

 tinguishable from the sterile branches. The development of 

 the archegonia has not been followed completely, but to judge 

 from the stages that have been observed and the mature arche- 



12 



