Asexual Reproduction in Hepaticae. 131 
often become detached and form new plants. In jfungermannia 
(Aplozia) caespiticia, Ekstrand 1 found within the perianth a number 
of young shoots, as many as fifteen in one case, arising amongst 
the archegonia. A still more interesting observation is recorded by 
Schiffner, 2 who found in Bazzania pectinata, collected in Amboina, 
a perianth from which there projected a slender shoot bearing small 
leaves. This shoot had arisen within the calyptra or fertilised 
archegonium, and appeared to spring from the base of the 
sporogonium itself. The latter was well developed, but had not 
grown beyond the calyptra, which had been ruptured by the 
adventive shoot. Schiffner was unable to determine exactly 
whether this shoot had arisen from the inner surface of the calyptra 
or from the base of the sporogonium itself, but the former would 
appear to be the more likely place of origin. 
Under the heading of caducous branches may be placed the 
leafy “ propagula ” described by Evans 3 as occurring in some species 
of Leptolejeunea and Drepanolejeunea , which live epiphytically on 
trees in tropical America. Each of these “propagula” arises 
immediately behind an ordinary lateral leaf and may be regarded 
as a short bud-like branch, bearing discoid leaf-like organs the cells 
of which secrete mucilage ; by means of these adhesive organs, the 
branch after separation from the main shoot becomes attached to 
the substratum and grows to form a new plant. 
In Frullania fragilifolia , the hood-shaped lower lobe (“lobule” 
or “ auricle ”) of each leaf is joined to the upper lobe only by a very 
narrow stalk, consisting of two cells, so that it readily becomes 
detached. Berggren* observed that when the lobule becomes free, 
or even whilst it is still attached to the plant, it gives rise to a leafy 
shoot. A single cell on the margin of the cup-like lobule grows and 
divides by intersecting walls, which cut out a tetrahedral apical 
cell from which the young shoot takes its growth. 
In Pteropsiella frondifonnis , a remarkable form discovered by 
1 Ekstrand, K- V., Anteckniugar ofver Skandinaviska lefvermos- 
sor. Botaniska Notiser af Nordstedt, 1880. 
2 Schiffner, V., Ueber exotische Hepaticae. Nova Acta d. K. 
Leop.-Car. Akad., Band 60, 1893, Nr, 2; p. 260, Taf. 11, 
Fig. 11. 
3 Evans, A. W., Hepaticae of Puerto Rico. I. The species of 
Leptolejeunea. Bulletin of the Torrey Botanical Club, Vol. 
29, 1902, p. 496. JI. Drepanolejeunea. Ibid., Vol. 30, 1903, 
p. 19. 
4 Berggren, S., Jakttagelser ofver mossornas konlosa fortplant- 
ning genom grodknopparoch med deni analoga Bildningar. 
Akademisk Afhandling, Lund, 1865, p. 26; Tab. iv., 
Fig. 26-28 
