THE Kazan Society of Naturalists continues its useful work of exploration. The last volume of its Memoirs (Trudy Obscheslva Esteslvoispytatdey pri Kazansrom Universitete, vol. xii.) contains two papers by the late M, Shell, on the botanical geography of the provinces of Ufa and Orenburg, being a list of 1054 Spermatophores already known from these two regions which have an intermediate flora between that of South-Eastern Russia and that of the Caspian Steppes. A most useful addition to the knowledge of the flora of these provinces is contained in the second paper by the same author, which gives a list of no less than 511 species of Sporophores (28 Vascular plants, 49 Mosses, 2 Chargæ, 181 Algæ, 94 Lichens, and 157 Fungi). The importance of this addition may be seen from the fact that, before M. Shell's work, only 39 species of Sporophores were known from these two provinces. It is worthy of notice that M. Shell has found among the Algæ the Asterionella Formosa, Hassel, which has been discovered in England and was found on the Continent only by Brébisson in France, and by Heibcrg in Denmark. The death of M. Shell in 1881 at Vilno was a great loss to Russian science. In the same volume M. Bekarevitch publishes his “Materials for the Flora of Kostroma,” being a list of 514 species of Phanerogams and 18 Cryptogams. M. Flavitzky publishes his researches into the pitchers of different Conifers. The author has studied the deviations of their planes of polarisation, and has found that the value of the angle of deviation is quite characteristic for different pitchers; it varies from —42°.2 (Pinus abies) to - 13°.1,- l0°.9, and - 9°.6 for the Pinus sylvestris, P. cembra, and Abies sibirica, and from + 9°.1 to + 27°.2 for the Abies balsamea and Larix europœa. We must notice also the elaborate researches, by A. Dogel, into the structure of the retina of the Ganoid fishes. These researches fill a gap which was pointed out many times; they are accompanied by excellent plates engraved at Leipzig.