376 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Algae. 
Stichids and Tetrasporanges of Dasya.* * * § — Mr. B. W. Barton de- 
scribes the development and structure of these organs in Dasya elegans. 
The stichids are scattered along the axis without any apparent order, 
and spring from ordinary vegetative cells. The tetrasporauges are pro- 
duced in them in acropetal succession, and their cells are connected with 
one another by protoplasmic threads. 
Actinococcus.t — Prof. F. Schmitz adduces additional arguments in 
favour of his view that the so-called “ nematheces ” on the frond of 
species of Phyllopliora are in reality the sporangial fructification of an epi- 
phytic alga of doubtful position among the Phaeosporeae, since the sexual 
organs are unknosvn. The typical species of this epiphytic genus, 
Actinococcus roseus, constitutes the so-called cystocarps ol P. Brodisei 
and of P. interrupta. Other species occur as epiphytes on different 
species of the genus Gymnogongrus. On three other species of Phyllopliora, 
P. Heredia, nervosa, and rubens, nematheces have also been described ; 
and these prove also to be the tetrasporanges of an epiphytic alga re- 
sembling Actinococcus, which, however, the author separates as a dis- 
tinct genus under the name Colacolepis. The diagnoses of these two 
genera are given in detail. The filaments of the epiphyte penetrate into 
the tissue of the host, and the cells of the two become closely united 
with one another. The epiphyte developes as an incrustation on the 
outer surface of the st'alk-like basal portion of proliferous lateral shoots 
of the host-plant, the appearance of which they sometimes altogether 
change. 
M. M. Gomont | confirms, in a general manner, the observations of 
Schmitz. The parasitic alga is composed of two parts, an epiphytic 
and an endophytic. Two kinds of tubercular protuberances are found 
on Alinfeltia plicata , one due to the attacks of animals or bacteria, and of 
the nature of a gall ; the other the fructification of a parasitic alga 
allied to Actinococcus. 
Structure of Caulerpa.§ — Herr P. Klemm objects to the term “uni- 
cellular ” as applied to Caulerpa prolifera and similar organisms. They 
should be regarded rather as “ symplasts,” composed of a number of 
energids in Sachs’s use of the term. The plasmode contained in the 
symplast is capable of independent nourishment, through its chlorophyll. 
He considers also the ordinary view of the purpose of the cellulose 
beams — viz. that they serve to give solidity to the plant — to be the 
correct one, rather than Noll’s, || that their main purpose is the convey- 
ance of nutritive substances. By growing specimens in the dark, and on 
the klinostat, the author established the fact that the formation of the 
foliar prolifications is entirely dependent on light. 
Low Forms of Algse.^I — Herr B. H. Franze gives details of the 
structure and life-history of the following freshwater Algae (and Proto- 
* Studies Biol. Lab. Johns-Hopkins Univ., v. (1893) pp. 279-82 (6 figs.). 
f Flora, lxxvii. (1893) pp. 367-418 (1 pi. and 8 figs.). 
; Journ. Bot. (Morot), viii. (1894) pp. 129-35. 
§ Flora, lxxvii. (1893) pp. 460-86 (5 figs.). || Cf. this Journal, 1889, p. 558. 
^ Oesterr. Bot. Zeitschr., xliii. (1893) pp. 202-5, 247-52, 282-6, 346-50, 381-6 
(1 pi. and 2 figs.). 
