592 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



States. The chapters on " Preservative Treatment " methods of creosoting 

 and shrinkage are all deeply interesting, and particularly so to British 

 timber-merchants who adopt almost similar ways of prolonging the life of 

 many of our native timbers. Skidding and weighing telegraph poles is 

 well depicted in the illustration at page 6 ; while the many carefully 

 compiled tables show how thoroughly the United States Department of 

 Agriculture go into the matter of seasoning and preserving timbers. — 



A. D. W. 



Preservative Treatment of Hemlock and Tamarack Cross- 

 Ties, The seasoning and. By W. F. Sherfesee (U.S.A. Dept. Agr., Forest 

 Service, Circ. 132). — Throughout the United States quite a revolution has 

 taken place in the kinds of timber used for railway ties. Not so long ago 

 oak was mainly used for this important purpose, and when oak became 

 scarce Michigan arbor-vitae or Michigan cedar was resorted to as a substi- 

 tute. Like oak, however, arbor-vitae has had enormous demands on its 

 restricted supply ; hence the railways were, for a third time, called upon to 

 find some other more plentiful wood, with the result that to-day hemlock 

 and tamarack are now almost exclusively employed. Many interesting 

 notes regarding these two woods, such as the source of materials, seasoning, 

 and storing away, are recorded in the pamphlet under notice, while the 

 tables and illustrations go far in assisting the text. — A. D. W. 



Prickly Pear as a Farm Crop. By David Griffiths (U.S.A. Dep. 

 Agr., Bur. Plant. Ltd., Bull., 124). — An account of experiments in 

 cultivating the prickly pear, a plant useful for cattle after the spines have 

 been singed off, a process apparently not difficult. The prickly pear is a 

 valuable crop in districts such as Southern Texas, where the climatic con- 

 ditions suit it, and are at the same time liable to be disastrous to other 

 green crops. — M. L. H. 



Pyrus sinensis. By 0. Stapf (Bot. Mag. tab. 8226).— Nat. ord. 

 Rosaccae ; tribe Pomeae. Manchuria and Korea. Tree 30-40 feet high, 

 cultivated ; leaves ovate, 2-4 inches long ; flowers 4-9-rlowered ; corymbs 

 white ; fruit (wild) globose, with numerous lenticels, 7 inches diameter. — 



G. H. 



Raphionacme utilis. By N. E. Brown (Bot Mag. tab. 8221).— 



Nat. ord. Asclepiadaceae ; tribe Periploceae. Angola. Perennial herb 

 with a turnip-shaped tuber 2-5 inches diameter ; leaves in 2-5 pairs ; 

 blade 1 inches long ; flowers in small terminal cymes ; corolla \ inch 

 diameter, bright purple.— G. H. 



Rhodazalea Crouxii (Journ. Soc. Nat. Hort. Fr. ; June 1908, 



p. 229). — This plant was produced by Messrs. Croux of Val d'Aulnay, and 



is a cross between Rhododendron ochroleucum and Azalea mollis. It is 

 said to be an interesting and attractive shrub. — M. L. H. 



Rhododendron, Branch Cankers of. By Hermann von Schrenk 

 (Rep. Miss. Bot. Gard. 1907, pp. 77-80; 2 plates). — A description of 

 cankers on Rhododendron maximum in the Appalachian Mountains 

 formed round dead branches without either fungal or insect attack. 



G. S. B. 



