370 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



a half times as great as that when the roots were cut, or cleanly trimmed 

 (p. 35). Another effect, at present unexplained, is the great response 

 made by bush fruits, especially gooseberries, to the use of animal 

 manure, and the almost entire absence of effect when the same 

 treatment is applied to apples. Still another unexplained point in 

 the behaviour of bush fruits was the adverse effect of planting goose- 

 berries and black currants in trenched ground at Rothamsted, as 

 compared with untrenched ground, while, in the case of fruit-trees 

 generally, the effect of trenching before planting was so slight that 

 the authors say it is not an operation on which the fruit-grower will 

 spend his money. Some of us are so conservative on this matter that 

 we cannot quite give up the idea that these results may be due to 

 something out of the ordinary in some other conditions present. 



The possible causes of the effect of grassing over the roots of trees 

 are still discussed at length (pp. 275-289), as well as the general subject 

 of the toxic action of one crop on another. Some of the other inter- 

 esting subjects dealt with, in addition to those lightly touched upon 

 above, are pruning, especially as regards newly planted trees, spring 

 frosts, the alternate fruiting of trees, mussel scale, currant gall (or big 

 bud), and other pests, silver leaf, potato disease, and the action of 

 various washes. 



In conclusion, a good index and chapter-analyses add to the value 

 of the book for ready reference. 



" The English Rock-Garden." By R. Farrer. 2 vols, lxiv + 504 

 -f- viii + 524 pp. 8vo. (Jack, London, 1919.) 3 guineas net. 



The author of this work set himself no light task when he planned 

 its dual character. At first sight it suggests the proverbial result 

 of endeavouring to sit upon two stools. Increasing acquaintance 

 with its contents, and testing its pages in search of desired information, 

 show that the task has been brought to an admirable finish. 



One half of the plan was to treat plants already grown in rock 

 gardens, or likely to be grown therein, somewhat after the fashion 

 in which the Abbe Coste has dealt with the native plants of France 

 in his most useful book ; that is, to lay stress on the most noticeable 

 and distinguishing characters by which one species can be distin- 

 guished most easily from another. For this purpose, Mr. Farrer turned 

 to the original Latin diagnoses of the plants, and has selected from 

 them the essential points, that he may make them available to all his 

 readers in short English descriptions. 



The other aim he keeps in view is, while making these descriptions 

 as definite and authoritative as their Latin originals, yet to express 

 them in the conversational and often picturesque or quaint English 

 he has such a gift for employing. 



Thus we find a complete absence of botanical terms, except such 

 as calyx-lobe, axii, corolla-tube, &c, which should prove strange to 

 no one who owns a garden or a gardening book. 



To test the value of this new dictionary of rock-garden plants, one 



