798 JOUENAL OF THE EOYAL HORTICULTURAL SOCIETY. 



varieties. C. Turczaninowii var. polyneura from W. China is perhaps 

 the most beautiful of all, with elegant foliage and fruit. 



Corylus Avellana is the common hazel. G. Golurna is widely distri- 

 buted in Europe and Asia. C. maxima or tuhulosa bears larger nuts. 

 From North America we get C. americana, also known as humilis or 

 serotina, and C. rostrata. C. ferox from Nepaul and Sikkim attains a 

 height of 33 feet, and bears its nuts in clusters, which are protected by 

 long spikes. C. heterophylla grows in Manchuria, E. Mongolia, Korea, 

 and Japan. C. pontica, a variety of C. Avellana, is found in the 

 neighbourhood of Trebizond. The nuts form an important article of 

 commerce in Asia Minor. G. Sieboldiana from Japan, C. mandschurica 

 from Korea and Manchuria, G. californica from California, Washing- 

 ton, and Oregon, and C. Fargesii from Central China, are all varieties 

 of G. rostrata. G. calyculata is a variety of G. americana, and 

 G. tihetica is a variety of G. ferox. Three varieties of C. heterophylla 

 were discovered in China in 1899, namely, sutchuensis , yunnanensis, 

 and Grista-galli. A large tree growing at an altitude of 6,000 to 7,000 

 feet in Yunnan, formerly described as Tilia chinensis, appears to be a 

 variety of C. Golurna. G. intermedia is a hybrid derived from 

 G. Avellana and G. Golurna. — S. E. W. 



Hemp, The Cultivation of, in the United States. By L. H. 



Dewey {U.S.A. Dep. Agr., Giro. 57; 7 pp.; 1 plate). — An account 

 of distribution, cultivation, harvesting profits, &c. On the latter point 

 the net profit is estimated at $20 from an acre. — E. A. Bd. 



House Flies and Formalin. By C. French {Jour. Agr. Vict. 

 July 1910, p. 480). — To suppress flies, take a soup-plate and cut a 

 couple of sheets of thick blotting-paper to fit into the bottom; half an 

 inch of clean damp sand under the blotting-paper will help to retain the 

 moisture on a hot day. Saturate the paper with water and sprinkle it 

 over, first with sugar, then with a quarter of a teaspoonful of formahn 

 (diluted with a spoonful of water, so that it will spread all over the 

 exposed surface). Place the plate in a well-lighted spot, preferably on 

 the floor, and the flies, attracted by the sugar, are quickly affected by 

 the formalin, and usually drop dead on the side of the plate. Formaliu, 

 however, evaporates after a time, so it may be necessary on a hot day to 

 renew it at intervals. — G. H. H. 



HydPilla sp. hortus Henkel. By F. Henkel {Gartenflora, 

 vol. lix. pt. iv. pp. 84-45; 1 fig.). — A beautiful water-weed, valuable 

 for an aquarium, is described, with a sketch. It is sold under the 

 incorrect name of Hydrilla verticillata, from which it exhibits marked 

 points of difference. — S. E. W. 



Insect Foes of the Onion, Leek, and Garlic. By Pierre Lesne 

 {Rev. Hort., June 16, 1910, pp. 281-284; col. plate).— A very interest- 

 ing article on the various insects which attack these vegetables, the 

 plate showing them in their various states, and the letterpress de- 



