566 SUMMARY OF CURRENT RESEARCHES RELATING TO 
in connection with the tetrasporc-m other-cells. They are rod-shaped 
and somewhat curved, and are larger than those of Stypocaulon, and 
probably also than those of Fucus ; the convex side always faces the 
nucleus. They are usually parallel, but may also be at right-angles 
to one another. They are not altogether homogeneous, but appear to 
consist of small granules. From the centrosome radiate very delicate 
threads of protoplasm which lose themselves beneath the chromato- 
phores and granules which have collected round the nucleus in a some- 
what dense zone. In the daughter-nuclei resulting from the first 
division of the tetraspore-mother-cells, the centrosome and its rays 
are found on the polar side, the greater number of the rays running 
in a tangential direction to the nucleus. 
From the remarkable similarity in the structure of the cells to those 
of Fucus and Styjpocaulon , and the fact that it possesses motile swarm- 
spores, the author is induced to place Dictyota among the Phaeosporeae. 
Sexuality of the Tilopterideae.* — M. C. Sauvageau denies to the 
monosporous sporanges of the Tilopterideae the designation of oogones, 
maintaining their non-sexual character. He proposes to remove Ecto- 
carpus pusillus from that genus and from the Ectocarpaceae, and to place 
it in the Tilopterideae under Acinetospora , to which genus Heterospora 
Vidovichii should also be referred. In A. pusilla he has found unilo- 
cular sporanges containing bodies which present all intermediate stages 
between aplanospores and zoospores. The monospore of A. pusilla con- 
tains only a single nucleus ; it is an organ of vegetative propagation, a 
propagule. Before escaping from the sporange it is enclosed in a deli- 
cate membrane, preventing all possibility of impregnation. In the 
other Tilopterideae the monospores are sometimes uninucleated, some- 
times multinucleated. Although some species have antherids, no sexual 
process is known, and the monospores germinate directly. The Tilo- 
pterideae have, therefore, no very near alliance to the Cutleriaceae ; their 
nearest allies are the Ectocarpaceae, which they closely resemble in their 
vegetative structure. 
Sexuality of the Sphacelariaceae.f — M. C. Sauvageau has discovered 
male sexual organs, antherids, on SpTiacelaria hystrix. They resemble 
the multilocular sporanges in form and size, but have smaller chambers, 
and are orange-red, while the sporanges are dark brown. No unilocular 
sporanges were observed, and the “ multilocular sporanges ” are probably 
oogones and their “ spores ” oospheres. The dehiscence of the antherids 
takes place in precisely the same way as that of the “ sporanges,” each 
loculus bursting separately. The antherozoids are pear-shaped, with a 
red spot, while the “ zoospores ” are oval and much larger. No conju- 
gation with the supposed oospheres was detected. 
The antherids of the Sjehacelariaceae closely resemble those of the 
Tilopterideae ; and the author now regards the Ectocarpaceae, Tilo- 
pterideae, and Cutleriaceae as forming an alliance not only among them- 
selves, but also with the Sphacelariaceae. 
Conjugation of Swarm-spores in Scytosiphon.J — Herr P. Kuckuck 
has been able to establish the occurrence of conjugation between swarm- 
* Comptes Rendus, cxxvi. (1898) pp. 1581-3. f Tom. cit., pp. 1672-5. 
X Her. Deutscfi. Bot. Gesell., xvi. (1898) pp. 35-7 (7 figs.). 
