328 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Horticultural Picket Line, The. By Frederick Maskew {U.S.A. 

 Si. Com. Hort. Cal., Bull. July 1913, vol. ii. No. 7, 6; figs.). — 

 The author describes the measures used to prevent the entry of the 

 Mexican orange maggot into CaHfornia. — V. G. J. 



Horticulture in Ohio (U.S.A. Exp. Stn., Ohio, Circ. 103 ; 1909). — 

 In this report some results of apples blooming and setting are com- 

 pared, and a discussion is reported on spraying against fungi, spray 

 injury, and spraying against market -garden diseases and pests. 

 In spraying against tomato-leaf spot, it was found that although 

 disease was checked and crop increased, maturity was delayed, and 

 the cost of spraying more than equalled the value of the extra crop. 



Costs of spraying orchards, with valuable data as to apple-growing 

 in Southern Ohio, are given. — C. P. C. 



Hydrocyanic Acid Gas in Horticulture. By F. Pilkington 

 Sargeant and F. C. Edwards {Gard. Chron. July 25, 1914, p. 65). — 

 Records nature and history of this gas, its suitability for destruction of 

 insect pests, principal causes of failure, directions for use in special 

 cases, and ends with three useful lists of 



(a) Six typical fumigations, with results. 



{h) Plants uninjured by phosphoric-cyanide process. 



id) Plants injured by same. — E. A. B. 



Hydrocyanic Acid Gas, Influence of Various Light Intensities 

 and Soil Moisture on Susceptibility of Cucumbers to Damage by. 



By G. E. Stone {U.S.A. Exp. Stn., Mass., Ann. Rep. 1912, p. 61, 

 Jan. 1913).— The influence of varying degrees of light intensity 

 and of soil moisture upon the development of cucumbers is described, 

 and it was found that burning of foliage after fumigation with hydro- 

 cyanic acid was greatest in plants grown under poor light conditions, 

 and that anything that causes the development of imperfectly matured 

 tissue tends to the burning of the foliage. — F. J. C. 



Hypericum Ascyron {Bot. Mag. tab. 8557). — North-Eastern 

 America and Eastern Asia and Japan. Nat. Ord. Hypericaceae, 

 Trihe Hypericeae. Herb, half-woody, 3-4 feet high. Leaves 

 sessile, 2\ inches long. Petals if inch long, i inch broad. Flower 

 nearly 4 inches across, yellow. Stamens in five groups. — G. H. 



Insect Pests and Plant Diseases, Control of {U.S.A. Exp, 

 Stn., Cornell, Bull. 283, 1910). — A brief illustrated description of 

 various well-known plant diseases and pests, with formulae for remedies, 

 and a general spray calendar. — C. P. C. 



Insect Pests, Garden and Truck Crops. By C. E. Sanborn 

 {U.S.A. Exp. Stn., Oklahoma, Bull. 100, Oct. 1912 ; 70 figs.). — This 

 treatise covers all the more important insect pests of the market 

 and garden crops of Oklahoma. General treatment for each species 

 is given, with formulae of sprays, poisoned baits, &c. — V. G. J. 



