Asexual Reproduction in Hepaticae. 
*59 
Diplophyllum albicans. G. polygonal, 1-celled, in yellowish 
clusters on the leaf-margin, towards the tips of the smaller upper 
and the larger lower lohes. Both the elongated cells of the 
“ midrib ” and the polygonal cells on each side of this take part in 
the production of the gemmae, the leaves often becoming eroded 
and truncated in consequence (Fig. 7). 
Fam. 5. Stephaniuoideae. In several species of Radula , the 
leaves frequently bear, either on the margin or the lower surface, 
scattered discoid gemmae, each consisting of a plate of cells, 
circular or oval in outline. The writer has followed the development 
of the gemmae in R. complanata. Each gemma arises from a single 
marginal cell, which grows in size and becomes further distinguished 
from the cells on either side by containing from one to four small 
brown oil-bodies, in addition to the large oil-body normally found in 
each of the leaf-cells in this species. These extra oil-bodies do not 
appear to arise by division or budding from the larger one, but are 
developed independently by segregation of the protoplasm to form 
a stroma, in which oil-drops soon appear. The cell then undergoes 
repeated divisions, the small oil-bodies passing into the newly-formed 
cells, so that ultimately each cell of the gemma contains one of 
these bodies, which becomes enlarged until it reaches about the 
same size as the oil body of the ordinary leaf-cell. The gemma is 
attached to the leaf-margin by a narrow base consisting of one or 
two cells, and shows on its distal margin a large apical cell, tri¬ 
angular in surface view, from which the young leafy shoot arises, 
when the gemma becomes detached and begins to germinate. 
Similar gemmae are found in R. germana and R. Lindbergii , which 
occur in Britain. In some tropical species of Radula , e.g., R. 
tjibodensis, the gemmae are larger than in R. complanata , and some 
of the marginal cells are modified to form organs of attachment, 
regarded by Goebel 1 as rhizoids of arrested growth, by which the 
gemma fixes itself to the substratum (leaves and trunks of trees). 
Fam. 6. Plcurozioideae. In this family, represented by the 
single genus Rleurozia (Physiotium), gemmae do not appear to have 
been yet observed. 
Fam. 7. Bellincinioideae. In Porella rotundifolia, from Brazil, 
Schiffner 2 figures discoid gemmae on the lower surface of the leaf, 
evidently resembling those of Radula and various Lejeuneae. 
1 Goebel, K., Kpiphytische Fame und Muscineen. Ann. du 
jard. hot. de Buitenzorg, Vol. 7, 1887. 
2 vSchiffner, V., Ueber exotische Hepaticae; Taf. 6, big. 2. 
