NOTES AND ABSTRACTS 



287 



gone into, and much useful advice and information are given. The writer 

 lays stress — and very properly — on the point that no wall garden should 

 be formed in a p )sition where the wall itself has not a distinct raison 

 d'etre, and the same rule should always be carried out in regard to pergolas 

 and other structures. Directions are given for the best ways to build 

 walls according to their position, whether as a support to banks or as 

 screens or boundaries. Advice is also given as to the best plants to use. 



G. S. S. 



Weather, the Relation of, to the Setting of Fruit. By U. P. 



Hedrick (U.S.A. Exp. Stn. Neiu York, Bull. 299, 1908).— Observations 

 of the dates of blossoming have been made over six years, and the 

 different varieties of each fruit are divided into early and late bloomers. 

 The average duration of flowering from first blossoms to petals having 

 dropped is, in the case of apples, nine days ; pears, seven days ; peaches, 

 eight days ; plums, seven days ; cherries, seven days ; grapes, ten days. 

 It will be noticed that this time is only half to two-thirds as long as in 

 England. The effects of temperature, frost, wind, rain, &c, are dealt with 

 in reference to the setting of fruit. Temperatures are given at which 

 the setting of the fruit is injured, whether in bud, in blossom, or in setting 

 fruit. Cross-fertilization is dealt with, and varieties flowering at the 

 same time recommended to be planted in proximity to one another to 

 favour fertilization. — C. H. H. 



Wood, Mechanical Principles in the Formation of. By K. 



Metzger {Nat. Zeit. Land- For st, vol. vi. pp. 249-273, May 1908).— The 

 mechanical principles involved in the building of timber-trees are her6 

 examined in detail. Special attention is given to the causes of excentric 

 growth, a subject which has been much discussed. The paper is well 

 illustrated, and is an important contribution. — W. G. S. 



