zoology and botany, microscopy, etc. 61 
scribes a fresli-water alga from the island of Wangerooge, differing from 
Scliizochlamys only in the brown colour of the chromatopliores. 
Fructification of Chnoospora.* — From a study of the fructification 
of Chnoospora fastigiata, especially from the presence of cryptostomatcs 
forming the centre of sori of plurilocular sporanges, Miss Ethel S. 
Barton removes that genus from the Sporochnoideae, and places it among 
the Encoeliaceae, near to Hydroclathrus and Colpomenia. 
Action of Light on Mesocarpus.f — Mr. F. J. Lewis confirms pre- 
vious observations as to the effect of light iu causing a turning of the 
plate of chlorophyll in the cells of Mesocarpus, amounting after 30 
minutes to an angle of 90°. In diffused light the chlorophyll-plate 
places itself at right angles to the incident light ; while in strong sun- 
light the edge of the plate is turned towards the source of insolation. 
On continued insolation the plate becomes curved. 
Structure of Diatoms.J — Herr P. Mitrophanow furnishes a contri- 
bution to this subject in a detailed account of a marine species of Stria- 
tella. He describes its external form, the structure of the shell and of 
the chromatophores, the pyrenoids, and the nuclei. The valve consists of 
a number of bands or pleurae , attached to one another by their margins, 
which are readily separated from one another by pressure. He claims 
to have observed gelatinous pseudopodes passing through openings in 
the valve. The pyrenoids are not solitary, but are grouped together 
in spheres and rosettes. The only mode of division of the nuclei 
observed was a direct one ; karyokinetic division he believes to take 
place in diatoms only under exceptionally favourable conditions. 
Structure of Codiacese.§ — Herr E. Kiister gives the results of the 
study of the Adriatic species of Codiaceae, belonging to the genera 
Codium , TJdotea , and Halimeda. 
In the tliallus of Codium two kinds of filament are to be distin- 
guished, — the first with narrow diameter running either in a tangential 
((7. bursa, adhaerens ) or in a longitudinal ( C . tomentosum ) direction ; the 
second broad, peripheral, and springing vertically from the former. 
The former kind the author terms “ axial,” the latter “ palisade-tubes,” 
these latter being merely the ends of the first kind of filament. From 
the base of each palisade-tube springs a slender filament by sympodial 
branching, which again takes up the original direction of the axial 
filament. The palisade-tube is always finally cut off from the support- 
ing axial tube by a septum consisting entirely of cellulose, and resulting 
from the gradual extension inwards of a thickening-ring near the base 
of the palisade -tube. The “hairs” of Codium ( C . tomentosum ) are 
narrow erect branches springing from near the apex of the palisade- 
tubes, and nearly, but not quite, completely septated from it by a 
cellulose-thickening formed on one side only near their base. They are 
probably aborted sporanges. The thallus of Codium is fixed to the 
substratum by numerous long bent attachment-filaments. 
In TJdotea (JJ. Desfontainii ) and Halimeda (H. Tuna ) there is no 
* Journ. Linn. Soc. (Bot.), xxxiii. (1898) pp. 507-8 (ljpl.). 
f Ann. of Bot., xii. (1898) pp. 418-21. 
t Flora, lxxxv. (1898) pp. 293-314. § Tom. cit., pp. 170-88 (5 figs.). 
