NOTES AND ABSTRACTS 



301 



Alfalfa, Arabian. By R. McKee {U.S.A. Dep. Agr., Bull. 119, 

 pp. 25-30). — Arabian alfalfa has large pale leaflets, soft, hollow 

 stems and soft crowns and roots, and is hairy. It can only be grown 

 in a very mild climate. Its life period is three years. It is severely 

 damaged by close pasturing or heavy tramphng, and cannot be 

 recommended. — 5. E. W. 



Ampelopsis megalophylla [Bot. Mag. tab. 8537).— China. Nat. 

 Ord. Ampelidaceae. Chmbing shrub. Leaves compound, 2-3 

 pinnate. Leaflets 5 inches long. Flowers green, very small. Fruit, 

 red-purple to blackish, J inch across. — G. H. 



Anthers, The Mechanism of Opening. By M. Schips {Beih. Bot. 

 Cent. xxxi. Abt. i. Heft 2, pp. 119-208, Dec. 1913 ; with 6 figs.). — 

 This article is almost a monograph of all that has been written on this 

 subject, and contains numerous original measurements of cells and cell- 

 thicknesses both in the open and in the closed conditions. The author 

 concludes that it is unnecessary to bring in the idea of cohesion, for 

 the contraction theory is sufficient. The contraction (shortening) of 

 isolated cells and the air contents of the anthers during the various 

 stages of opening show that this is so. True cohesion folds do not 

 occur. Neither the vacuum method of Steinbrinck nor artificial 

 opening of the anthers by means of water-absorbing substances as 

 practised by Hannig proves a cohesion mechanism. 



During the process of drying, .the fibres or fibrous cells contract as 

 follows : In cross-section the contraction is 15 per cent, parallel to and 

 25 per cent, at right angles to the unthickened part of the cell ; longi- 

 tudinally (along the chord — " Sehne ") 10 per cent. The unthickened 

 membrane contracts 45 per cent, at right angles to the fibres, and 

 therefore is chiefly responsible for the opening ; the fibres act especially 

 as resistants against the locular wall. The adaptations in cell structure 

 and in the arrangement of the anthers to the method of opening are 

 clearly brought out. With the same breadth, the higher the cell, the 

 stronger the contraction. 



Unfortunately there is not space to give details of the author's 

 measurements of injured and uninjured cells, &c., which must have 

 required an extraordinary amount of labour. There is an excellent 

 bibliography. — G. F. S. E. 



Apple and Cherry Ermine Moths, The. By P. J. Parrott and 

 W. J. Schoene {U.S.A. Exp. Stn., New York, Tech. Bull. 24, Nov. 1912 ; 

 9 pis., 8 figs., I map). — These insects were introduced on imported 

 nursery stock: Yponomeuta malinellus Fell., which lives on the 

 apple, and Y. padellus L., which is a more general feeder, showing 

 preference for hawthorn, plum, and cherry. Both species are common 

 and destructive fruit pests in Europe. — V. G. J. 



Apple, Brown Rot Canker in. By E. S. Salmon {Gard. 

 Chron. Aug. i, 1914, p. 85 ; 3 figs.). — Further investigations of 



