Das Pflanzenphysiologische Prakticum

Abstract

IN the new edition of this standard book, the general arrangement of the first edition has been for the most part adhered to, but in other respects great changes have been made. Nearly every section has been rewritten and enlarged, a large number of new experiments have been added, and in every case great care has been taken to give full details for carrying out the observations described. Among- the sections added, the following may be mentioned: on the relation of the stomata to assimilation; an account of experiments on species of the natural family Papilionaceæ, illustrating their relation to the bacteria normally found in their roots; on nitrification, including an experiment on nitromonas, one of the remarkable organisms capable, without the action of light, of forming organic substances from inorganic materials. Another addition is the section on mykorhiza. In dealing with the intercellular system of plants, it is strange that Prof. Detmer still quotes the intercellular space, which accompanies the bundles of Zea Mays, as an example of a passage which is of importance in the exchange of gases and the aëration of the tissues; while it is almost certain that this passage is chiefly serviceable in conducting water in the plant. The sections dealing with transpiration have been materially enlarged and improved, although it is difficult to see how the author could be inclined towards Westermaiers and Godlewski's theories after Strasburger had so completely answered them. It is to be noted that, in an appendix, Prof. Detmer appears to accept the theory which regards the upward motion of the sap as due to the tension set up by the evaporation taking place in the leaves, and transmitted downwards through the water-columns in the tracheidal system. He, however, apparently by an oversight, attributes this theory to Prof. Askenasy, who himself, in the paper describing the theory, acknowledges the priority of its English authors.

Das Pflanzenphysiologische Prakticum.

Von Dr. W. Detmer. Mit 184 abbildungen, zweite völlig neu bearbeitete Auflage. (Jena: Fischer, 1895.)