F. Cavers. 
1 2 6 
In several species of Aneura (A. multifida , pinnatifida , palmata , 
pinguis), there are formed, especially at the tips of the thallus-Iobes, 
large numbers of two-celled gemmae. These gemmae were figured 
accurately by Hofmeister, 1 but Goebel 2 was the first to call attention 
to their development, which differs from anything hitherto observed 
in other Hepaticae, except Metzgeria. The writer has carefully 
followed out the process of gemma-formation in A multifida (Fig. 1). 
Fig. i. Aneura multifida. I. Part of a plant, showing the ends of the 
branches covered with gemmae ; x 5. II. Cells from the end of a branch, 
showing stages in formation of gemmae; x 150. III. Two fully-formed 
gemmae, still within the cells; that 011 the left is escaping through the 
pore in the outer cell-wall; x 300. IV. Free gemma, in optical section, 
showing nuclei and chloroplasts ; x 400. 
The gemmae are developed endogenously, each being formed within 
one of the cells of the thallus and escaping by the rupture of the 
outer cell-wall. The cell-contents contract away from the cell-wall 
and become covered by a delicate membrane of cellulose. The 
nucleus then undergoes division; the two daughter-nuclei move 
towards the opposite ends of the ovoid protoplast, and a median 
septum is formed. A large portion of the outer wall of the mother¬ 
cell becomes absorbed, and the two-celled gemma slips out of the 
opening thus formed. The gemma contains numerous chloroplasts 
embedded in dense protoplasm; sometimes starch is also present. 
The writer has occasionally found that further divisions occur in 
the gemma before its liberation, so that instead of being two-celled, 
as is usually the case, the gemma may consist of three or even four 
cells whilst still enclosed within the mother-cell. 
1 Hofmeister, W., Vergleichende Uiitersucliungen, 1851, Taf. vi., 
Fig. 29a. 
2 Goebel. K., Die Musciueen (Scheiick’s Hantlbuch der Botauik, 
Vol. ii.), 1882, p. 338. 
