240 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the genus belongs to the Florideae (Batrachospermese), rather than, as 
Schmitz and Kirchner suggest, to the Phaeosporese. The following are 
the chief points of structure on which this view is founded : — The violet 
or purple pigment, which corresponds to that found in several other 
fresh-water Florideae, but to nothing known in the Phaeophyceae ; also 
the starch-like granules, which are coloured red-brown by iodine. The 
nature of the membrane and of the protoplasmic connections of the cells. 
The non-motile naked spores. Similar structures occur, among the 
Phaeophyceae, only in the Tilopterideae and Dictyotaceas ; and with these 
orders Thorea has certainly no genetic affinity. The absence of sexual 
organs of reproduction may simply be the result of imperfect knowledge, 
as has been the case with many other genera of Florideae. 
Turbinaria.* — Miss E. S. Barton gives a monograph of this genus of 
Fucaceae (Sargasseae), with the following generic diagnosis, — Caulis 
simplex v. ramosus, folia et receptacula gerens ; foliis petiolo tereti ant 
triquetro aut trialato, interdum in vesiculum intumescente, laminam 
peltatam triquetram v. orbicularem sustinente; receptacula racemosa v. 
corymbosa in axilla folii emergentia, dioica v. monoica, interdum her- 
mapbrodita ; radix fibrosa. The number of species described is nine, of 
which three are new, — T. Murrayana from New Guinea, T. tricostata 
from Guadeloupe, and T. dentata from Macassar. The description of the 
morphological structure is taken chiefly from T. conoides. The thallus 
is well differentiated into stem, leaf, and root. The growth of the 
stem is apical, but the author is unable to determine whether it takes 
place by means of a single cell or a group of initial cells. The air- 
vesicles are regarded as in all cases metamorphosed leaves ; they are 
formed by the rending apart of the central tissue in young leaves. The 
view is advocated that the “ sterile conceptacles ” which contain para- 
physes only are of equal antiquity, from a phylogeuetic point of view, 
with those which contain reproductive organs. 
Caulerpa.f — Mr. G. Murray describes three new species of Caulerpa, 
— C. Holmesiana from Algoa Bay, G. Fergusonii from Ceylon, and 
C. phyllaplilaston from Yucatan ; anil gives reasons in favour of the view 
that the Caulerpcae are more nearly related to the Valoniaceae, rather 
than to the verticillate Dasycladeae. 
Reproductive Cells of Hydrodictyon.f — Herr G. Klebs has under- 
taken a further examination of the formation and structure of the repro- 
ductive cells in Hydrodictyon reticulatum, and gives the following as the 
more important results attained. 
The cells which are destined for non-sexual propagation become 
very finely granular ; the grains of starch are absorbed, and its substance 
distributed through the whole of the chlorophyll-layer in an extremely 
fine form ; the nuclei increase rapidly and become uniformly distributed. 
The green layer of protoplasm which contains the nuclei is penetrated 
by fissures which finally unite into a delicately branched system, so that 
it appears as if broken up into a number of bauds united with one 
* Trans. Linn. Soc. Lond., iii. (1891) pp. 215-26 (2 pis.). 
f Tom. cit., pp. 207-13 (2 pis.). 
% Bot. Ztg., xlix. (1891) pp. 789-98, 805-17, 821-35, 837-46, 853-62 (1 pi.). Cf. 
this Journal, 1891, p. 227. 
