642 JOUKNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



six hours, at a temperature of 140-149''. At the commencement of the 

 sixth hour it is raised to 168°. During the six hours the door is opened 

 once or twice to see if the prunes acquire a good brown colour and 

 gloss. If there is no gloss, the temperature is too low : the fire should 

 be forced. At the close of six hours the prunes commence to wrinkle. 

 The truck is taken out again and once more left for an hour in the open 

 air. 



Finishing. — As soon as the truck is removed the air-entrances are 

 closed and the temperature is raised to 212° F, The truck is again 

 introduced, and the temperature falls to 140°. The air-entrances remain 

 closed during about an hour, until the thermometer-pane shows slight 

 moisture. The air-entrances are then opened to carry off the excess 

 of steam. For six hours heating is continued, so as to gradually reach 

 167° towards the fifth hour. The air-entrances are constantly open 

 during the last period of finishing, so that moisture may not soften the 

 prune, which w^ould cause delay and reduce quality. Towards the sixth 

 hour the door is opened, and the fruit is sometimes left for another 

 hour in the oven, so as to ensure complete drying. In a recent trial 

 1,119 lb., in two charges, dried down to 437 lb. prunes, or 35.7 per 

 cent, of the fresh fruit; 1,054 lb. of wood were burnt, or 241 lb. per 

 100 lb. of finished prunes. — G. H. H. 



Frost Injury. By D. Eeddick {U.S.A. Fruit Growers' Associa- 

 tion, New York; Proc. 1912). — A serious amount of damage was done 

 by frosts to fruit-trees in 1911, of which this is an account. The 

 symptoms of the damage were feeble growth, sickening, yellowing, 

 and finally death of foliage. This damage was sometimes confined 

 to one side of the tree. Close inspection revealed canker spots either 

 near base or in crotch of tree. In peaches and cherries gumming 

 occurred. In young apples and pears the bark, at first black, changed 

 colour to yellow or brown and clung tightly to the wood. On vines 

 swellings somewhat like those produced by ** crown gall " appeared 

 during the summer. A discussion of the general effects of frost is 

 given, and it is said that a moderate cutting-back prevents a great 

 amount of damage. — F. J. C. 



Geotropy and Statoliths. By Arthur Block (Beih. Bot. Cent. 

 Bd. 28, pp. 422-452; 6 figs.). — The author gives results of a number 

 of experiments with Lepidium, Helia7ithuSy Vicia, Trifolium, and 

 Setaria seedlings, which show that the use of potash-alum (to remove 

 starch) either produces traumatic curvatures, that can easily be mis- 

 taken for geotropic curvatures, or may injure the roots. 



No geotropic curvature was found when the roots were freed of 

 starch. Other bodies in the roots occasionally produced geotropic 

 movement. The statolith theory is not therefore contradicted by the 

 experiments of Pekelharing. — G. F. S, E. ^ 



Ginseng-, The Diseases of, and their Control. By H. H. 



Whetzel and J. Rosenbaum (U.S.A. Dep. Agr., Bur. PI. Ind., Bull. 



