8(3 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Protophyta. 
a. Schizophycese. 
Cell-contents of the Phycochromacese. * * * § — In opposition to the 
observation of Zacharias, Herr Y. Deiniga finds, in the species of 
Phycochromacese (Cyanophycese) examined — viz. Oscillaria princeps and 
Frolichii, Aphanizomenon Jlos-aquee, and Nostoc sp. — true chromatophores 
having the form of a more or less perforated plate in contact with the 
cell-wall. Ho states also that the cell-nucleus is of a different nature 
in Algse (e. g. Spirogyra ) from that in the higher plants. In Apha- 
nizomenon and Nostoc the chromatophore is coarsely reticulate. 
Both these statements are controverted by Herr E. Zacharias, | who 
asserts that the bodies observed by Deiniga can have nothing to do with 
true chromatophores. For the examination of the cell- walls, and of 
the process of cell-division in the Cyanophycese, he strongly recom- 
mends Gomont’s process, of treating with 50 per cent, solution of 
chromic acid, washing, and staining with methyl-blue. Both the cell- 
walls and the contents are thus coloured ; the imperfect walls in the 
cells in process of division can be detected, the cell-contents having 
receded from them. "Within the cell are the greatly diminished and 
constricted protoplasmic cell-contents. 
Structure of Diatoms.l: — Mr. E. M. Nelson describes some new high 
power diatom resolutions. Among them are the following : — Coscino- 
discus apiculatus, consisting of a crown of small perforations round the 
primary, and of still smaller perforations within the primary ; these 
latter are so fine that they are difficult to observe. Sysiephania diadema ; 
in the comparatively coarse primaries there arises a zone, and they are 
connected by delicate walls of silex, which are above the hexagonal 
structure, and which pass at right-angles over it. A fragment of a 
Co8cinodiscu8, consisting of an isolated secondary structure which has 
broken out of the primary areolations. Plenrosigma angulatum with 
postage-stamp fracture. A Navicula, with a fine pipe running through 
the centre of the raphe which opens to the exterior at the extremity of 
the valve, and which then passes down the valve to the central 
nodule. From the central nodule there is a fine tube leading to the 
interior of the valve. These tubes occur also in kindred species. 
New Diatoms.§ — -M. J. Brun publishes, in 12 plates, 120 micro- 
photographs of new species or varieties of diatoms. They have been 
prepared from apochr'omatics, and the beautiful drawings have been 
made with the camera lucida, according to the method pursued in 
Schmidt’s Atlas. 
Moller’s Plates of Diatoms. — Herr J. D. Moller’s Atlas of “Licht- 
drucktafeln Mollerschen Diatomaceen - Praparate ” consists of 59 
beautiful folio photographic plates of diatoms. The first ten plates 
each contain impressions of a very large number of species arranged 
* Bull. Soc. Imp. Nat. Moseou, 1891, No. 2, 28 pp. (1 pi.). Cf. this Journal, 
1890, p. 371. t Bot. Ztg., xlix. (1891) pp. 664-7. 
I Journ. Quekett Micr. Club, iv. (1891) pp. 315-9 (1 pi.). 
§ Mem. Soc. Phys. et Hist. Nat. Geneve, xxxi. (1891) (12 pis.). See Bot, 
Centralbl,, xlviii. (1891) p. 170. 
