22 The Botanical Gazette. [January, 
or they mayvarise directly from protonemal structures, as in 
Buxbaumia. # 
One may then classify the metanemal structures of the 
Muscinez thus: 
Secondary leafy stems. 
Leafy stems } Primary leafy stems. 
Metanema of Muscinez : 
tao a 
It is probable that neither in the Hepaticze nor in the 
Musci is there any gametophyte that is not susceptible of di- — 
vision into protonema and metanema. It has been affirmed — 
that Frullania, Anthoceros and a few other Hepatice develop 
directly from the spore as monomorphic structures (Nees ab — 
Esenbeck), but this is not borne out by the researches of Leit- _ 
geb* who figures for Anthoceros at least a well-marked pro- 
tonema. And for Frullania and its allies among the foliose 
Jungermanniez, while Hofmeister believed that the proto- 
nema might be suppressed, the researches of Grénlund® have 
well demonstrated that the protonemal structure is constantly — 
present in one form or another. Leitgeb himself concludes 
that the protonema is a normal stage for Frullania, Radula 
and the rest. § — 
Below the Hepatice there are undoubted gametophytes 
without any marked differentiation into protonema and met- | 
anema and others in which the differentiation is a matter of 
grave doubt. Of the first group, CEdogonium and Bul: 
bochete may be cited; of the second, Chara, Tolypella, © 
Lychnothamnus and their allies. For the gametophytic 
structure that does not show any differentiation into pro- 
tonema and metanema and stands lower than the hepatic 
gametophyte, I propose here the name of archenema. € 
Coleochete thallus is an example of typical archenema. The 
classed as metanema. 
*Goebel, On the simplest form of moss. Ann of Bot. 6:355. 1892. é 
*Leitgeb, Die Anthoceroteen. 20. f/. r. 1879. ei 
SGrénlund, Mem. sur la germination de quelques hépatiques. Ann. SC 
Nat. Bot. IV. 1: a 
*Leitgeb, Die foliose Jungermannieen 63. 1875. : 
7Vines, The pro-embryo of Chara. Journ. of Bot. 1878. . 
