654 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Structure and Development of Dendroceros.* — Prof. D. H. Campbell 
gives the following as the main results of his study of this epiphytic 
genus of Hepatic®. 
In its apical growth and in the form of the thallus, Dendroceros 
differs widely from other genera of Hepatic®. The type of apical cell is 
that found in Pellia epiphylla , and in the homosporous Ferns, especially 
Osmunda, where the prothallium resembles the thallus of Dendroceros 
also in the definite midrib and the occasional development of leaf-like 
lobes. The archegone corresponds in its structure to that of the other 
Anthocerote®, and is intermediate in character between Notothylas and 
Anthoceros. The antherid is solitary, and arises, as in the others of the 
order, endogenously. The first wall of the embryo is longitudinal, as 
in Anthoceros , but the first transverse wall determines the limits of the 
foot, as in Notothylas . The origin of the archespore is from the amplii- 
thece, as in the other genera, but it is less massive than in either of these. 
The division of the archesporial cells into sporogenous and sterile is 
less regular than in either of the other genera, and the primary arche- 
sporial cells may be transformed directly into sporogenous cells without 
any further divisions. The capsule is destitute of stomates. 
Algae. 
Cystocarp of Delesseriaceae.f — Mr. R. W. Phillips has studied the 
development of the cystocarp in several species of Delesseria and Nito- 
phyllum, and lays stress on the following points as presenting some 
divergence from conclusions arrived at by other observers. The carpo- 
gonial branch is invariably four-celled, as is universally the case in 
the Rhodomelace®. Although usually arising singly on an inner cell of 
the cortex, the carpogonial branches occasionally appear in pairs. The 
author was unable to confirm the formation of a second chamber de- 
scribed as separated from the spore-containing cavity by the middle 
layer as a kind of diaphragm. The fusion of the auxiliary cell with 
neighbouring cells at the “ placenta,” so general in the FJoride®, is 
strikingly absent in Delesseria ; nor does it occur in Grinnellia. An 
anterior auxiliary cell, cut off from the pericentral cell, occurs in most 
Rhodomelace®, and in all Ceramiace®. When the cells adjacent to the 
central cell in a fertilised protocarp become charged with nutriment 
prior to the formation of the gonimoblast-filaments, they become multi- 
nucleate, as many as eight or ten nuclei at times occurring in one cell. 
As regards their systematic position, the Delesseriace® are undoubt- 
edly nearly allied to the Rhodomelace®. 
Myrionemace®4 — M. C. Sauvageau has studied the structure and 
mode of reproduction of this small family of epiphytic and endophytic 
sea-weeds belonging to the Ph®ospore®. 
In Myrionema, vulgare he distinguishes the following four structures : 
— (1) A creeping thallus, with marginal growth from transverse division 
and dichotomous branching of its cells ; (2) the rhizoids, multicellular 
filaments growing downwards from the thallus ; (3) the hairs, springing 
* Journ. Linn. Soc. (Bot.), xxxiii. (1898) pp. 4G7-78 (2 pis.). 
t Ann. of Bot., xii. (1898) pp. 173-202 (2 pis.). Cf. this Journal, 1S9G, p. 546. 
t Ann. Sci. Nat. (Bot.), v. (1897) pp. 161-288 (29 figs.). 
