ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 599 
Systematic Position of the Bangiaceae.* — Prof. T. Johnson adduces 
arguments in contravention of Schmitz’s proposal to separate the Bangi- 
acem ( Bangia , Porphyra , Wildemania, Erythrotrichia, Goniotrichum ) alto- 
gether from the Florideae. He would retain them as the lowest family 
in this class, grouping all the other families under the sub-class 
Eu-Floride^. 
The Bangiacete agree with the Eu-Florideae in the colour of the 
chromatophores ; in the reproduction both by non-sexual spores and by 
sexual organs ; in the male organs being “spermatia” (pollinoids) ; and 
in the mode of impregnation. The differences consist mainly in the 
form of the thallus ; in the continuity of the cell-contents in the Bangi- 
aceae by fine strands of protoplasm passing through the cell- walls ; in the 
non-sexual spores being usually tetraspores in the Eu-Florideae, mono- 
spores, bispores, or tetraspores in the Bangiaceae ; in the position of the 
“ spermatanges ” (antherids) ; in the position of the carpogones, and the 
rudimentary condition of the trichogyne in the Bangiaceae ; and in the 
arrangement of the carpospores. This latter point the author believes 
to be dependent on the nutrition, on facility of formation, and on the 
mode of distribution of the spores. 
Irritability of Spermatozooids of Fueaceae.t — Dr. J. Bordet has 
studied the irritability of these bodies, and finds that, in normal con- 
ditions, they are not affected by numerous reagents ; thus, they neither 
seek nor avoid light, are not attracted to the egg-cell by the influence of 
chemical substances ; they are affected only by contact, and to this they 
are very sensitive. The various Algae — Fucus platy carpus, F. vesiculosus, 
Himanthalia lorea , and Ascophyllum nodosum — which have been studied 
often, grow side by side in great quantities ; as the products of the re- 
productive cells generally escape at low tides, they are not, as a rule, 
carried far. Small quantities of water flow slowly from one plant to 
another, and are sufficiently charged with male and female products to 
make a meeting inevitable. Moreover the number of reproductive 
elements is so considerable that many may be lost without the species 
running any risk of being discontinued. 
Bulbils of Chaetonema.J — Dr. J. Huber has observed, on Chsetonema 
irregulare , the formation of propagative organs of the nature of bulbils, 
on the same filaments as those which produce zoospores. 
Development of Pediastrum.§ — Prof. R. Chodat and Dr. J. Huber 
confirm the observation of Braun as to the mode of multiplication of 
Pediastrum by the formation of gelatinous vesicles in which new indi- 
viduals are formed by successive bipartitions. The formation of these 
gelatinous vesicles they found to be dependent on the nature of the 
medium. The vesicle is formed from a cellular coating intermediate 
between the true cell-wall of each cell and the protoplasm which it 
encloses. Pediastrum occupies a position intermediate between the 
Scenedesmeae and the Hydrodictyeae. 
* La Nuova Notarisia, v. (1894) pp. 636-47. Cf. this Journal, 1893, p. 763. 
t Bull. Acad. Roy. Belg., lxiv. (1894) pp. 888-96. 
+ Bull. Herb. Boissier, 1894, p. 163 (1 pi.). See Hedwigia, xxxiii. (1894.) Rep., 
P* 78. § Ann. Sci. Phys. et Nat., xxxi. (1894) pp. 386-7. 
