AGRICULTURAL BOTANY. 723 



Agricultural bacteriology, H. L. Kussell aucl E. ii. Hastings (Madison, 

 Wis.. I'jit'K i>i>- yi+.l'il. fiox. 23). — This book is desiguetl to give a concise, com- 

 prehensive treatment of the many and varied relations which bacteria bear to 

 problems of farm life, and from its breadth, compactness, and simplicity should 

 be valuable to those who wish to acquire a general knowledge of the principles 

 of modern agricultural bacteriologj'. 



The book is divided into 5 sections as follows: (1) General bacteriology, in 

 which the structure, growth, and distribution of liacteria and their artificial 

 cultivation are given : (2) relation of bacteria to milk and other dairy products, 

 including contamination, preservation, and fermentation of milk, bacteria in 

 butter and cheese making, and the marketing of milk; (3) relation of bacteria 

 to disease in live stock, its nature, treatment, and prevention, with general 

 directions for the use of various disinfectants; (4) relation of bacteria to the 

 soil; and (5) food preservation and diseases of plants. Under section 4 the 

 effects of bacteria on the mineral elements of the soil, ammonification, nitrifica- 

 tion, denitrification, and fixation of nitrogen, bacteria in manure and the best 

 methods of handling it are discussed. In addition the subject of water supply 

 and sewage disposal on the farm is treated under this section, a septic tank 

 suitable for farm pnrposos being described and figured in detail. 



A method of bacteria counting', H. Fischer (Ccntbl. Bald, [etc.'], 2. AM., 

 25 (1909), No. l-h-18, pp. .'i57-Jf59). — Several nutrient media are described, with 

 tables showing the number of bacteria developed on each. 



Media for the quantitative estimation of soil bacteria, J. G. Lipman and 

 I'. E. Brown (CeiitbJ. Bakt. [etc.], 2. Aht., 25 {1909), Nrj. l'f-18, pp. //.'/7-//5^).— 

 The usual gelatin media were rejected on account of their high nitrogen content 

 and rai>id liquefaction by certain of the soil bacteria. The alkaline bouillon 

 agar was replaced by a so-called synthetic agar, made up of 1,000 cc. tap water, 

 10 gm. dextrose, 0.5 gm. dipotassium phosphate, 0.2 gm. magnesium sulphate, 

 0.05 gm. potassium nitrate, and 20 gm. agar. This forms a slightly acid medium, 

 offers the best conditions for the development of a large number of colonies, 

 and checks the too rapid growth of the spreading colonies, thereby preventing 

 their interference with the development of other species. The optimum of 

 acidity for quantitative estimation of soil bacteria was found to be an acidity 

 equivalent to 5 cc. of normal hydrochloric acid per liter of the medium used and 

 was obtained in the synthetic agar by the use of 0.5 gm. dipotassium phosphate. 



Soil bacteriolog'ical investigations, C. Barthel (Centbl. Bakt. [etc.], 2. 

 Aht.. 25 {1909), No. 1-.',. pp. lOS-125, flu. 7 ) .—Previously noted (E. S. R., 21, 

 p. 528) from a Sv^^edish source. 



On the occurrence of nitrobacteria in the sea, P. Thomsen ( Ut)er das 

 Vorkommen von NitroJtaktericn iin Meerc. Inaug. Diss., Univ. Kiel, 1908, pp. 

 28). — The author reports the finding of the nitrite organism in samples of ooze 

 from the bottom of the Kiel Fiord but not in the sea water. Plankton, or the 

 fixed algte. It was also found in similar samples of soil from the vicinity of 

 Helgoland and in slime from the bottom of the bay of Naples, but only in 

 samples taken near the land. 



Morphologically the nitrosomonas and nitrobacter from the salt water were 

 not different from those isolated by Winogradski from cultivated soils of 

 western Europe. Physiologically the salt water organism appears to be a form 

 especially adapted to the salt content of its environment. Variations in this salt 

 content retard its oxidizing power. The salt water organism is as dependant 

 upon heat as the nitrobacteria of cultivated soils. 



Thermophilous bacteria in the Tropics, E. de Kruijff {Bill. Dept. Agr. 

 Indes Neerland., 1909, No. 30, pp. 1-11 ; Centbl. Bakt. [etc.], 2. AU., 26 {1910), 



