800 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY, 



Seed Collecting (U.S.A. Dep. Agr., Year Book 1912, pp. 433- 

 442 ; 4 plates). — A most instructive account of methods used in 

 collecting forest tree seeds. The winter hoards of squirrels offer a 

 ready source of fir cones. An example of the magnitude of the work 

 carried on was the gathering of 20,000 bushels of cones of Pinus 

 monticola in 191 1 . A very readable and interesting article. — E. A . Bd. 



Seed Sterilization. By Ivy Massee (Jour. Bd. Agr., vol. xx. 

 No. 9, pp. 796-801 ; 2 plates). — De Zeeuw, Pinoy, and Magrou having 

 shown the efficacy of hydrogen peroxide (H 2 0 2 ) as a sterilizing agent 

 the author was led to experiment with a view to ascertaining its action 

 on fungus spores and on the germination of seeds, as it appeared 

 probable that this substance would prove of value in preventing the 

 spread of plant diseases by fungus spores on seeds. 



Seeds of twelve plants and spores of eleven species of fungi were 

 tested. The hydrogen peroxide used was that known as " commercial, 

 10 vols.," and was not diluted. 



None of the fungus spores experimented with germinated after 

 immersion for two hours. 



All the seeds, however, were capable of withstanding immersion 

 for four hours, and seven sorts were not killed by immersion for 

 twenty-four hours. 



In nearly every instance the germination of the treated seeds 

 was retarded, seeds immersed for four hours being on an average one 

 or two days later in appearing above ground than untreated seeds of 

 the same kind. After treated seeds have germinated growth is rapid, 

 and in a short time the plants are equal in size and vigour to those 

 from untreated seeds. 



" For all practical purposes, soaking seed in hydrogen peroxide 

 for three hours will kill all superficial fungus spores and the seed will 

 not be injured." — A. S. 



Senecio Kirkii (Bot. Mag. tab. 8524). — Family Compositae-, 

 tribe Senecionidae. New Zealand. Shrub, 7-15 feet high. Leaves 

 variable, linear oblanceolate, 14-4* inches long. Corymbs 4-12 inches 

 across. Heads numerous, 1J-2 inches wide. Ray-florets about 10, 

 white. Disk florets yellow.— G. H. 



Shade Trees, Pests of. By A. F. Burgess (Jour. Econ. Entom. 

 vol. v. pp. 172-178, April 1912 ; plates). — An account is given of the 

 spraying of trees in towns. The author also gives estimates of 

 the cost of machines and of labour, and recommends the immediate 

 attention of town authorities to trees that are in the least affected by 

 pests. He points out that it is often cheaper to spray trees than to 

 remove them after they are dead from the attacks that have been 

 neglected. — F. J. C. 



Shade Trees, Three Pests of. By G. W. Herrick (four. Econ. 

 Enlom. vol. v. pp. 169-172, April 1912) — The elm-leaf beetle (Galeru- 

 cella luteola) was kept in check by spraying with lead arseniate at a 



