Evans .— Vegetative Reproduction in Metzgeria. 297 
Echmomitrium violaceum , Corda, Deutschl. Jung, (in Sturm’s Flora), 
8i ; pi. 22. 1832. 
Metzgeria violacea , Dumort., Recueil d’Obs. sur les Jung., 16. 1835. 
Metzgeria furcata , var. gemmifera , Nees, Naturg. der europ. Leberm., 
iii, 488. 1838. 
Metzgeria furcata , var. violacea , Dumort., Hep. Europ., 139. 3874. 
Metzgeria furcata , var. aeruginosa , Moore, Proc. Irish Acad., 2nd Ser., 
ii, 665. 1876. 
Metzgeria furcata, var. fruticulosa , Lindb., Acta Soc. Faun. FI. Fenn., 
i, 40. 1877. 
By some of the earlier writers AT. fruticulosa was supposed to be 
identical with Jungermannia violacea , Ach., 1 a species based on specimens 
collected at Dusky Bay, New Zealand, in 1773 ’ by Sparrman. These 
specimens were examined by Lindberg, who pointed out that they were 
distinct from the European plant. He referred them to Metzgeria conjugata , 
as a variety violacea , although he knew the typical M. conjugata only from 
the Northern Hemisphere. Judging from Lindberg’s description the variety 
violacea bears specialized gemmiparous shoots and is deserving of further 
study. In Stephani’s monograph of the genus Metzgeria neither M. fruti¬ 
culosa nor M. violacea is mentioned. 
Gemmae of Metzgeria and of other Bryophytes compared. 
Vegetative reproduction by means of gemmae is a phenomenon of 
widespread occurrence among the Bryophytes, and has been observed in 
all the orders except the Sphagnales and the Andreaeales. The various 
types of gemmae which have been found in the Bryales are fully discussed 
by Correns (’ 99 ), and the gemmae of the Hepaticae have been similarly, but 
more briefly, treated by Cavers (’ 03 ). According to Correns (p. 446) the 
power to produce gemmae (and similar reproductive bodies) is inherent in 
certain species, but absent from others, so that it ought to be regarded as 
a definite specific character. In most of the gemmiparous species of the 
Jungermanniales the gemmae are in the form of minute unicellular or 
bicellular bodies, but in the remaining species they are multicellular and 
sometimes show a greater or less degree of cell-differentiation. In a few 
cases such gemmae form solid masses of cells, as in Blasia and Cavicularia , 
but it is much more usual for them to be in the form of flattened thalloid 
structures, similar to those just described for Metzgeria. Gemmae of this 
type are by no means confined to genera in which the adult plant is 
a leafless thallus. They occur also in a number of leafy genera belonging 
to the Porelleae, Raduleae, and Jubuleae. In all of these sub-orders, 
however, as Goebel (’ 89 , p. 16) and others have pointed out, the spore in 
germinating first gives rise to a thallus, upon which the leafy shoot after- 
1 In Weber and Mohr’s Beitrage zur Naturkunde, i, 76, pi. 1, figs. 1-3, 1805. 
