NOTES AND ABSTRACTS, 



175 



Soil Bacteria and Decomposition of Nitrogenous Compounds. 



By Conrad Hoffmann (U.S.A. Exp. Stn. Wisconsin, 23 rd Ann. Bep. ; 

 October 1906). — The author finds that the numbers and character of the 

 bacterial flora of the soil are largely influenced by the nature of the 

 fertilisers used and by the character of the soil itself, the number being 

 smallest in sand and greatest in black marsh soil. The degree of 

 nitrogenous decomposition is, in a general way, directly dependent on 

 the total number of bacteria present, and the progress of the decom- 

 position is marked by numerous fluctuations, corresponding with the 

 fluctuations in the numbers of bacteria present. Large amounts of 

 ammonia are formed before nitrification becomes active without inter- 

 fering in any way with the subsequent development of the nitrifying 

 organisms. Blood and bran are much more easily decomposed than 

 bone meal and peat, and decomposition is most complete in black marsh 

 land, followed by clay, sandy loam and sand in the order named.— F. J. C. 



Soil Sterilisation. By A. D. Selby (U.S.A. Exp. Stn. Ohio, 

 Circ. 59 ; October 1906).— Kecommends drenching the old beds m which 

 tobacco has been grown with formalin at the rate of 2 lb. of formalin 

 (40 per cent.) to fifty gallons of water in order to destroy the fungi 

 Bhizoctonia, which causes " bed rot " and Thielacia, which causes " black 

 rot." The formalin must be allowed to evaporate before the seed is 

 sown. — F. J. C. 



Solanum Commersonii and S. C. Violet. By Labergerie (Bev. 



Hort. June 16, 1906, pp. 303-307 ; coloured plate).— A detailed account 

 of the appearance of the violet form and the result of subsequent culture 

 by M. Labergerie and others ; of interest to those who have followed the 

 recent controversy in connection with these potatoes as practically forming 

 its starting-point. — C. T. D. 



Specific Names for Garden Varieties. By S. Mottet (Bev. 

 Hort. February 16, 1906, pp. 97-99). — A much-needed protest against the 

 naming of new varieties as if they were species, the name of the species 

 proper being ignored, leading to great confusion. — C. T. D. 



Spinach, Mercury or Perennial. By G. Wythes (Garden, No. 



1796, p. 219 ; April 21, 1906). — In many parts of the country the above 

 plant is little known, yet few are cultivated more easily. In Lincolnshire 

 this plant is found in most gardens grown under the names of Mercury 

 and Lincolnshire spinach, but in the adjoining counties it is called ' Good 

 King Henry ' (Chenopodium Bonus Henricus). The plants are usually 

 propagated at this season (March or early April). It may also be raised 

 from seed sown thinly in the spring, as it is a quick grower, the seedlings 

 being planted out in dull weather in the early autumn in rich land in 

 rows 18 inches apart, half that distance between the plants. Grown thus 

 there will be good cutting material the next spring. It is propagated by 

 division early, and in well-manured deeply dug land. — E. T. G. 



Spraying 1 Notes. By E. Walker (U.S.A. Exp. Stn. Arkansas, 

 Bull. 95 ; 1907). — Spraying has frequently been disregarded, but the 



