392 PATHOLOGY [Bot. Absts. 



overhumid atmosphere, weakening through parasites. There results a reduction of the 

 somatic mass (nanism, Japanese dwarf trees, etc.). There occurs besides a reduction in the 

 growing period, the plant hastens towards completion of its development, and often pro- 

 duces abundance of flowers (dwarf fruit trees), when it may eventuate in a process of "sich 

 zum Tode bluhen" [blooming itself to death]. Opposed to the above occurs reduction in or- 

 gans (leaves, petals, and anthers; for instance, in poppy). Finally malnutrition may cause 

 reduction in diversity of organs. In Zea mais there may occur only staminate flowers; fern 

 prothallia produce only male sexual organs. (There occurs, so to say, spaying) On the 

 other hand, cleistcgamous flowers may develop (Impatiens). The struggle of the parts 

 within an organism is really a battle for the available nutritive substances. Upon this de- 

 pends the physiological malnutrition (sterility, latency of buds for decades). Malnutrition 

 is important in the development of each single organ, as well as for the general habit of the 

 plant. Norwithstanding physiological compulsion to permanent new production of organs, 

 long lived plants will only reach a certain dimension, and live to an average age. When the 

 distance from earth to crown is too long, there results a reduction in the crown — the tree 

 ages.—//. T. Gussow. 



2693. Matotjtschek. [Rev. of : Markowski, A. Botrytis cinerea als Parasit auf Aesculus 

 parviflora Walt, und Aesculus Hippocastanum. (Botrytis cinerea parasitic on Aesculus parvi- 

 flora and Ae. Hippocastanum.) Beitr. Biol. Pflanzen. 13. 347 p. 1917.] Zeitschr. Pflan- 

 zenkrankh. 29:65-66. 1919. 



2694. Matouschek. [Rev. of: Neumann, O. Absterben durch elektrischen Strom. 

 (Dying through electrical current.) Mitteil. Deutsch. Dendrol. Ges. 1917:237.] Zeitschr. 

 Pflanzenkrankh. 29: 54. 1919. — A robust linden tree at Naumburg a/S. grew in proximity 

 to a high voltage pole. During thunderstorms in 1916 the electrical earth currents circulated 

 through the branches towards a lightning conductor with which the pole was equipped, 

 giving rise to audible hissing. The tree gradually died. — H. T. Gussow. 



2695. Matouschek. [Rev. of: Rebmann. Absterbende Schwarzmisse. (Dying of 

 walnuts.) Mitt. Deutsch. Dendrol. Ges. 1917: 109-114. 3 fig.] Zeitschr. Pflanzenkrankh. 

 29: 53-54. 1919. — Dying and dead walnut trees occur in the forests of the Rhine near Strass- 

 burg. Author considers as cause soil conditions, water conditions, and the dense stand of 

 trees. Suggests periodical thinning of stand by cutting over. — H. T. Gussow. 



2696. Matouschek. [Rev. of : Rudau, Bruno. Vergleichende Untersuchungen iiber die 

 Biologie holzzerstorender Pilze. (Comparative studies on wood destroying fungi.) Beitr. 

 Biol. Pflanzen. p. 375-458, 6 pi. 1917.] Zeitschr. Pflanzenkrankh. 29: 63-64. 1919— Poly- 

 porus igniarius on the following new hosts: Ulmus campestris, Prunus cerasifera, Hippo- 

 phae rhamnoides. Forms of rots were studied on species of Betula, Salix, Populus, Pirus, 

 and Prunus. Is a typical wound parasite. — H. T. Gussow. 



2697. Matouschek. [Rev. of: Schwerin, Fritz, Graf v. Blasenrost auf Pinus aus- 

 triaca. (Blister rust of P. austriaca.) Mitt. Deutsch. Dendrol. Ges. 1917:212.] Zeitschr. 

 Pflanzenkrankh. 29: 63. 1919. — Record of this rust on single tree on Roman road near Epoy, 

 Belgium, where, for large distances around, Pinus strobus, Ribes, or Berberis cannot be found. 

 — H. T. Gussow. 



2698. Matouschek. [Rev. of: Vadas, Eugew Die Monographic der Robinie mit be- 

 sondrer Rticksicht auf ihre forstwirtschaftliche Bedeutung. (Monograph of Robinia with 

 special regard to its significance in forestry.) xiv 4- 252 p. 10 art prints, 30 text fig., 14 

 tables. Selmecbanya, 1914.] Zeitschr. Pflanzenkrankh. 29:49. 19l9. — The seventh sec- 

 tion of above publication deals with the enemies of Robinia, and with protective measures 

 against thorn. Among the vegetable parasites are mentioned Viscum album; Nectria cinna- 

 barina, affecting in one case 33 per cent of plants following injury with the hoe; Phytophthora 

 omnivora in seedlings; Polyporus sulphur eus, causing a dry wood rot; Pseudovalsa profusa 

 on young twigs and on leaves; Septoria robiniae, S. curvata, etc. Robinia is rarely injured by 

 spring frosts. Fall frosts kill the twigs without injury to the tree. — H. T. Gussow. 



