Beiträge zur Biologie der Pflanzen

Abstract

THE third part of Cohn's “Beitrage,” now before us, completes the first volume, and let us express the hope that we may have another volume before very long. Curiously, each of the three parts has been separately paged, an arrangement which renders it necessary to note the part as well as the page when the index is consulted. If we may judge from the size and price, each part has increased in importance, so that the third part has more papers and is nearly double the size of the first. In all the parts there have been papers of great interest and value, and those in the present part are in no way behind their predecessors. Dr. Cohn himself contributes three papers to the present part, Dr. J. Schrœter two, while Drs. L. Just, A. B. Frank, Richard Sadebeck, and Eduard Eidam, each one. The first paper is by Dr. Schrœter on the Development of certain Rust-Fungi. On Carex hirta, one of the Uredineae was observed which Dr. Schrœter believes to be Puccinia caricis of De Candolle; and as he had reason to suspect that AEcidium urticae of Schum was only a stage in the life history of P. caricis, experiments were made to ascertain definitely whether P. caricis was heterœcious, and if so, whether AEcidium urticae was one of the stages. Details of the experiment are given, and Schrœter concludes that AEcidium urtica is a stage of Puccinia caricis. In a note to his paper, Dr Schrœter mentions that Dr. Magnus, of Berlin, has made similar experiments with the same result, an important confirmation of the remarkable habit these curious plants have of changing from one host to another, and at the same time changing the form of their spores, a condition describee by De Bary long ago in the rust of wheat. A second form noticed by our author is a species of rust common on many grasses. It has many names, and Dr. Schrœter calls it Uromyces dactylidis, Ottli, (Uromyces graminis, Cooke). One stage is spent in our common grasses, such as Dactylis glomerata, Poa nemoralis, P. trivialis, P. annna, P. pratensis, c the Muscineae and Vascular Cryptogams having Spermatozoids, while the flowering plants have pollen and pollen-tubes, showing a certain analogy to the pollinodium of some of the Carposporeae. Beitrage zur Biologie der Pflanzen. Herausgegeben von Dr. Ferdinand Cohn. (Breslau, 1875.) Drittes Heft.