Ökologie. 183 



427) Osburn, The care of home aquaria. In: New York Aquarium Nature 

 Series, 63 S., 30 Fig., 1914. 



Der Verf. befaßt sich hauptsächlich mit der Beschreibung und dem Besatz 

 des „balanced aquarium". Dies ist nach einer von H. D. Butler 1858 gegebenen 

 Definition ein Behälter zur Aufnahme von Wasserpflanzen und -tieren, dessen 

 Wasser aber nicht gewechselt zu werden braucht. Das Wesen dieses bei rich- 

 tigem Besatz mit Pflanzen und Tieren unbeschränkt andauernden Gleichgewichts- 

 zustandes wird ausführlich besprochen. Sodann werden in der herkömmlichen 

 Weise die für die Haltung in Süß- und Seewasseraquarien hauptsächlich in Be- 

 tracht kommenden Pflanzen und Tiere u. dgl. abgehandelt. Auch die Einrichtung 

 eines Terrariums wird kurz besprochen. Die Schrift ist für Anfänger bestimmt 

 und wird ihren Zweck gewiß erfüllen. Steuer. 



428) Heald, P.D., and Studhalter, R.A., Birds as Carriers of the Chest- 

 nut-blight Fungus. In: Journ. Agr. Research, Vol. II, No. 6, S. 405 — 423, 

 Sept. 1914. 



The work described in this paper was undertaken in order to furnish positive 

 evidence as to whether birds actually do carry spores of the chestnut-blight f ungus, 

 Endothia parasitica. 



The 36 birds tested belonged to 9 different species. Of the 36 birds 32 were 

 those which are in the habit of climbing over the trunk and larger branches of 

 trees. Most of the birds were shot from blighted chestnut trees; some directly 

 from blight cankers. The bill, head feet, tail, and wings of each bird were scrubbed 

 with a brush and poured plates were made from the wash water, which was retained 

 and centrifuged for its Sediment. Of the 36 birds tested, 19 were found to be 

 carrying spores of the chestnut-blight fungus, Endothia parasitica. The viable spores 

 of the chesnut-blight fungus carried by two downy woodpeckers numbered 757,074 

 and 624,341, respectively, while a brown creeper carried 254,019. The cultures 

 from some of the birds showed from 2 to 14 times as many viable spores of the 

 chestnut-blight fungus as of all other fungi combined. The highest positive results 

 were invariably obtained from birds shot from two to four days after a period 

 ■of considerable rainfall. The rate of development in cultures always indicated 

 that the colonies of the chestnut-blight fungus originatedfrompycnospores; pycno- 

 spores were generally found in the centrifuged Sediments, while ascopores were 

 never detected. The birds were therefore carrying pycnospore only. Birds are 

 probably not very important agents in spreading the chestnut-blights locally, on 

 account of the predominance of other and more important factors of dissemina- 

 tion, as, for example, the wind. Pearl. 



429) Shaw, H. B., Thrips as Pollinators of Beet Flowers. In: U. S. Dept, 

 of Agr. Bull. No. 104, S. 1—12, July 1914. 



A description of experiments is given to show that the numerous species of 

 Thysanoptera are active agents in pollination. Among beet flowers they effect 

 both close pollination and cross-pollination. The Suggestion is made that certain 

 supposed mutations may really have been the result of unsuspected cross-pollination 

 by means of one or another species of thrips, whether in cereals supposedly not 

 susceptible to cross-pollination without the Intervention of man or in flowers which 

 were thought to have been isolated against cross-pollination. Pearl. 



430) Hedicke, Haus, Zur Kenntnis abnormer Gallbildungen. In: Sitzungs- 

 ber. Ges. nat. Freunde, S. 424—426, Taf. XI, Berlin 1914. 



