AGRICULTURAL BOTANY. 721 



The author has added much to the value of the text by including on each 

 page footnote annotations and title references to the more important and recent 

 works on the subject under discussion, while a brief statement of the technique 

 and methods to be used in performing cultural experiments under the different 

 groups is appendetl to each section, accompanied by footnote title references to 

 the more important and extended articles on technique. 



The book closes with an index of some 2,600 authors, representing in the ag- 

 gregate 7,000 titles on subjects relating to agricultural bacteriology, including 

 the results of investigations published during the year 1909 on this subject. 



Chilean fungi, C Spegazzini (Rev. Facult. Agron. y Vet. La Plata, 2. ser., 6 

 (1910), [)i). 3-205, figs. 133). — ^A taxonomic discussion is given of 326 species of 

 Chilean fungi, in which 8 new genei-a and about 222 new species are described. 



Experiments on the latent vitality of the spores of the Mucorineae and the 

 Ascomycetes, P. Becquerel {Compt. Rend. Acad. Sci. [Paris], 150 (1910), No. 

 22, pi>. l.'i37-lJ,39). — The spores of Macor mucedo, Miicor raccmosus, Rhizopus 

 niger, Sierigmatocystis nigra, and Aspergillus glaucus were slowly dried in 

 small sterilized glass tubes in the presence of baryta anhydrid for 2 weeks at 

 a temperature of 35° C. and then by means of a mercury vacuum pump, a 

 vacuum of less than 0.001 mm. was obtained and the tubes sealed air tight by 

 means of a flame. After remaining in this condition for about 12 months, the 

 tubes were subjected for 3 weeks to the temperature of liquid air ( — 180°), and 

 then without appreciable warming subjected for 77 hours to the temperature of 

 liquid hydrogen ( — 253°). About 13 months later, or 25 months from the begin- 

 ning of the experiments, the tubes were opened with all necessary precautions 

 against outside contamination and the spores sown in liquid sterilized nutritive 

 media. 



In about 10 hours the spores of the Mucorineje germinated and began to pro- 

 duce sporangia. Two days later the spores of Sterigmatocystis and Aspergillus 

 had also germinated and formed mycelia bearing numerous conidiophores. 



Studies in soil bacteriolog'y, IV. — The inhibition of nitrification by organic 

 matter, compared in soils and in solutions, F. L. Stevens, AV. A. Withers, 

 ET AL. (Ccnthh Bait, [etc.], 2. Aht., 27 (1910), No. J,-9, pp. 169-186).— A further 

 study (E. S. R.. 22, p. 427) on nitrification is reported in which the inhibiting 

 action of organic matter in solutions and in soils is compared. 



The authors claim as a result of their experiments that the inhibiting influ- 

 ence of organic matter (peptone or cotton-seed meal) is much greater in solutions 

 such as Omeliansky's than it is in soil water, and that nitrification can pro- 

 ceed vigorously in the soil in the presence of large quantities of such organic 

 matter as peptone, cotton-seed meal, or cow manure. In the light of these facts 

 the direct application of Winogradsky's conclusions (E. S. K., 11, p. 711) to the 

 field must be abandonetl, and with them any practices based on his conclusions, 

 and the activity of these soil bacteria must, in th^' future, be studied more 

 largely under their natural environments. It is claimed that organic matter 

 even to a large amount, as considered agriculturally, is not necessarily inimical 

 to the functioning of nitrifying organisms in the field. 



Some factors concerned in the fixation of nitrogen by Azotobacter, C. Hoff- 

 mann and B. W. Hammer (Wisconsin Stn. Research Bui. 12, pp. 155-112, figs. 

 2; Cenihl. Bal.t. [etc.], 2. Aht., 28 (1910), No. 1,-5, pp. 127-139).— A report is 

 made on iiivesfigafioiis coucerning the source of energy open to nitrogen-fixing 

 organisms, the various conditions that favor or retard their action, the elements 

 other than carbon that are necessary, and the form in which they are most 

 easily utilized by the bacteria. 

 65483°— No. S— 10 3 



