Andr eceales. 
25 
Fig. 69. Andrem. A to C, stages in development of the embryo sporo- 
phyte, in longitudinal section ; F to J, similar stages in transverse section ; 
K, diagrammatic view of the entire sporogonium after elongation of pseudo¬ 
podium and transverse rupture of the venter of the fertilised archegonium ; 
C, longitudinal section of fairly advanced sporogonium, showing the arche- 
sporium, calyptra, and vaginula, also the upper portion of the pseudopodium in 
which is inserted the foot of the sporogonium; M, part of a transverse section 
of a fairly advanced sporogonium, showing one of the dehiscence lines in 
the epidermis of the capsule-cell ; N, similar section of a ripe sporogonium. 
All the figures are somewhat diagrammatic ; c., col., columella ; cal., calyptra ; 
e., endothecium ; d.l., dehiscence line ; sp. s., spore-sac. 
nation of fresh or suitably preserved material would be of great 
interest, in order to determine whether or not we have here a 
transition from the peculiar dehiscence mechanism of the typical 
Andreaeales to that seen in Tetraphis. As shown by Goebel (2), 
the moist spores adhere to the edges of the slits, which close in wet 
weather, and become dry and loosened when the slits gape on 
drying. 
The germination of the spores and the peculiar forms of the 
protonema were investigated by Kuhn and also by Berggren 
(1). The spore begins to germinate and forms a cell-mass before 
the exospore is ruptured ; when rupture occurs, the superficial 
cells of the mass grow out separately to form filaments which grow 
apically, segments being cut off from the terminal cell by transverse 
walls. These filaments branch freely, some of the branches 
creeping over the substratum, while others grow upwards and turn 
green, others again growing into crevices in the rock and remaining 
colourless. The erect filaments may become cylindrical and 
produce flat leaf-like plates, hence the forms of the protonema are 
very diverse, and any of them may produce buds which grow into 
leafy shoots. Elaborate protonemata of a very similar kind occur, 
however, in various Bryales. 
LITERATURE OF ANDRE2EALES. 
1. Berggren, S. “ Studier ofver mossornas byggnad och utveckling. I. 
Andreaeaceae.” Lund, 1868; 30 pp. 
2. Goebel, K. “ Ueber die Sporenausstreuung bei den Laubmoosen.” 
Flora, 1895 ; 27 pp. 
3. Kuhn, E. “ Zur Entwickelungesgeschichte der Andreaeaceen.” Schenck 
and Leurssen’s Mitt. a. d. Gesammtgebiete d. Bot., 
Band I., 1870; 56 pp. 
4. Waldner, M. “ Die Entwickelung der Sporogone von Andrem und 
Sphagnum." Leipzig; 1887. 
The genus Andrem is also dealt with by Goebel (Organography), Lotsy 
(Vortrage, Band 2), Campbell (Mosses and Ferns), and in Engler and Prantl 
(Nat. Pflanzenfam.). 
