i 9 
Sphagnales. 
Mosses. The germ-tube given out by the spore is soon converted, 
by growth of its end-cells, into a flat discoid thallus, forming an 
irregularly lobed expansion one cell in thickness, attached by 
numerous rhizoids. The protonema may reproduce itself by 
sending out from its margin threads which give rise to discs, and 
these may later become separated as independent protonemata. 
Usually one leafy Sphagnum plant arises from each protonema, as 
a projection formed by active growth and division of a marginal 
cell at the base of the protonema; in this cell arise walls cutting 
out a three-sided apical cell, the segments cut out from this at once 
producing the young leaves. The fourth or fifth leaf shows the 
differentiation into green and hyaline cells; at first this differen¬ 
tiation is shown only in the lower portion of the leaf, the upper 
cells remaining uniform and green. 
Oehlmann (23) has shown that Sphagnum plants are able 
to produce protonemata and young leafy plants from practically any 
living portion of the mature gametophyte. The young Sphagnum 
plant, whether arising from primary protonema (produced on ger¬ 
mination of the spore) or from secondary protonema (in regenera¬ 
tion of portions of the mature plant) bears rhizoids which may 
twine like tendrils around old Sphagnum stems and other supports ; 
but as the plant developes it produces no more rhizoids, these 
absorbing hairs being unnecessary since the plant has such efficient 
means of absorbing water in its remarkable capillary system and 
its perforated hyaline cells. 
The affinities of Sphagnum will be discussed later, when the 
characters of the Andreseales and Bryales have been dealt with. 
LITERATURE OF SPHAGNALES. 
1. Braithwaite, R. “ The Sphagnacese or Peat-Mosses of Europe and North 
America.” London, 18S0 ; 88 pp. 
2. Campbell, D. H. ‘‘Mosses and Ferns.” London, 1905 (2nd ed.). 
3. Cardot, J. “ Repertoire sphagnologique.” Bull. Soc. Hist. Nat., Autun, 
1897; 200 pp. 
4. Cavers, F. ‘‘The Life History of a Peat Moss.” Knowledge, vol. 33, 
1910. 
5. Geleznov, N. ‘‘La Mousse des marais a-t-elle la propriety d’absorber l’eau 
liquide et la vapeur repandue dans l’atmosphih'e ? ” 
Bull. Soc. imp. St. Petersbourg, vol. 20, 1873, 
pp. 375-389. 
6. Goebel, K. “ Organography of Plants.” Englished. 
7. Horrell, E. C. “ The European Sphagnacete, after Warnstorf.” Journal 
of Botany, 1900. 
