Sphagnales. 13 
water-cells, and from the stem-leaves in having abundant chloro¬ 
phyll. The structural peculiarities of these leaves are obviously 
connected with their functions, the protection and nutrition of the 
developing sporogonium; owing to the scarcity of fibres in the 
cells, these leaves closely invest the young fruit instead of being 
stiff or curved outwards, and their abundant chlorophyll enables 
them to carry on active photosynthesis. Within the large 
enveloping leaves we find at the apex of the branch a small group 
of archegonia surrounded by a number of small leaves which for a 
long time remain in an embryonic or undifferentiated condition 
(Figs. 63, 64). The first archegonium is formed from the apical 
cell of the branch, and then from two to four others are developed 
around it; occasionally there are only two archegonia, or no more 
Fig. 64. Longitudinal section of female branch of S. compactum , showing 
fertilised archegonium with embryo. 
