Bacteriologie. — Pteridophyten. 347 



guten Erträgen, im Teiche mehr in der Anreicherung des Bodens 

 mit Stickstoff zum Ausdruck. Die Methoden zur Bestimmung der 

 N-bindenden Kraft der Feldböden können auch für die Teichböden 

 angewendet werden, bedürfen aber durch Feststellung der Leis- 

 tungsfähigkeit der N Bakterien im Wasser in Symbiose mit grünen 

 Wasserpflanzen einer Ergänzung. Matouschek (Wien). 



Lipnian, C. B. and P. S. Burgess. Studies on Nitrogen 

 Fixation and Azotobacter Forms in Soils of foreign 

 Countries. (Centralbl. Bakt. 2. XLIV. N" 17/23. p. 481-511. 1 

 plate. 1915.) 



The plan of the authors consisted in studying the appearance 

 of the cultures obtained from soil inoculation into a proper medium, 

 making a microscopic study of the mixed flora, isolating pure cultures 

 from the mixed flora plated out on mannite agar, studying the mor- 

 phology of these, and determining the nitrogen fixing powers in 

 ijoth Solutions and soils ofthose forms which, selected from the large 

 number of pure cultures, were distinctly different from one another. 

 Five gram portions of the soils to be tested were inoculated into 

 sterile 50 gram portions of the Lipman mannite Solution in 250 cc. 

 Erlenmeyer flasks and incubated for two weeks at 28 to 20° C. 

 Notes were taken frequently with reference to the appearance of 

 these cultures which are given below. At the end of two weeks 

 material from the mixed cultures was plated out on mannite agar 

 and the balance of the culture was analyzed for nitrogen in accor- 

 dance with the modified Guming method described by one of the 

 authors elsewhere. Sterile blanks were run to check all cultures 

 which in turn were run in duplicate. The authors were fortunate 

 in having at disposal a large coUection of soils from various parts 

 of the World which formed a portion of the celebrated soil collection 

 made by E. W. Hilgard (College of Agric. of Univ. California). 

 From this collection the authors selected 46 soils, representing 

 the following regions: Egypt, India, Japan, China, Syria, 

 Hawaiian Islands, Costa Rica, Spain, Italy, Russia, 

 Mexico, Canada, Samoa, Queensland , Galapagos Islands 

 etc. Most of these soils had been stored in tightly stoppered sam- 

 ple bottles for periods ranging from 15 to 20 years. New are the 

 species: Asotobacter smyrnii, Bacillus 29 n. sp. (from cultivated soil 



at Egypt), Bacillus 12 n. sp. (from Cernozem, Russia), Asoto- 

 bacter 24 n. sp. (from poor humus silt Guatemala). Strikingly 

 interesting species are: Asotobacter 25 var. A. vinelandii (Lipman, 

 J. G) from soil south of Aidin Smyrna, Asotobacter 45 Y3.r. A. 

 chroococcum (Beyerinck), Asotobacter 15 b. A. chroococcum (Beije- 

 rinck) from poor soil from Sinaloa (Mexico). 



Matouschek (Wien). 



Alderwerelt van Rosenburgh, C. R. W. K. van, Malayan 

 Fern Allies. Handbook to the Determination of the 

 Fern Allies ofthe Malayan Islands (ine 1. thoseof the 

 Malay Peninsula, the Philippines and New Guinea). 

 (Publ. by the Dept Agriculture, Industry and Commerce Nether- 

 lands India. XVI, 262 pp. Gr. S«. Batavia, 1915.) 



Gleichsam eine Ergänzung zu dem bekannten „Malayan Ferns- 

 Handbook" des Verf. Die Ergänzung betrifft die anderen Pterido- 



