332 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Prothallium and Embryo of Ban®a.* — According to Mr. G. Brebner, 
there is a close similarity between Dansea and the other two genera 
of Marattiacese, Angiopteris and Marattia , in the structure of the pro- 
thallium. The rhizoids possess a distinctly septate structure, resem- 
bling the protoneme of a moss. The development of the antherids of 
Dansea agrees in the main with that in the other two genera ; but the 
development of the archegones was not followed out. The concentric 
bundle of the primary embryonic stem shows an endodermal layer. 
Sorus of Dansea.')' — Prof. F. O. Bower describes the development of 
the sorus of Dansea , calling special attention to the points that single 
cells of the sporogenous group may develop as sterile cells, and con- 
sequently that, in Dansea , the identity of the sporange or loculus is not 
strictly defined. 
Muscinese. 
Gemmse of Mosses.J — Herr C. Correns describes in detail the gemmae 
of Georgia ( Tetraphis ) pellucida , which give rise to protonemal filaments. 
He finds a differentiation in the marginal cells of the gemma, a few of 
them being smaller, with thinner walls, and containing less chlorophyll, 
but more protoplasm, than the rest. These cells he terms nematogonous , 
since it is from them only that the protonemal filaments are developed. 
Whether the protoneme springs from a spore or from a gemma, the 
protonemal leaves which serve as assimilating organs are, as a rule, 
formed from its ascending branches ; but occasionally it puts up a 
much-branched “ fruticose protoneme ” ( Protonema-bdumchen ), similar to 
those of Andresea. These never develope into leafy plants, and are 
apparently the result of a feeble illumination ; they produce, however, 
gemmae abundantly, in all respects like the normal ones. No sexual 
organs were observed on the leafy plants. The author regards the 
gemmae as modified paraphyses. 
Similar differentiated nematogonous cells were observed in the 
gemmae of Pleuridium nitidum var. bulbilliferum and Zygodon viridis- 
simus , and, in a rudimentary condition, in Encalypta streptocarpa. 
Calymperes.§ — M. E. Bescherelle gives a monograph of this entirely 
tropical and subtropical genus of Mosses, of which he enumerates 
180 species. In the leaves he describes, under the term cancellinse, 
groups of large hyaline cells at the base of the leaf arranged in rows 
parallel to the vein ; the term tseniolse being applied to rows of much 
smaller cells between these and the margin. The size and form of the 
cancellinse are used in delimiting the subsections. 
Algse. 
New Genera of Florideae.|| — Mr. E. A. L. Batters establishes the 
following new genera from British seas : — 
Colaconema. — Thallus microscopic, consisting of rose-red creeping 
* Rep. Brit. Ass. (Ipswich), 1895, p. 857. 
t Proc. Roy. Soc., lix. (1896) pp. 141-3 ; Ann. Bot., x. (1896) pp. 105-7. 
X Ber. Deutseh. Bot. Gesell., xiii. (1895) pp. 420-32 ; xiv. (1896) pp. 94, 5 (1 pi. 
and 2 figs.). § Ann. Sci. Nut. (Bot.), x. (1895) pp. 247-308 (5 figs.). 
|j Joura. of Bot., xxxiv. (1896) pp. 6-11. 
