2(38 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



earthenware tubes about two to three inches in diameter and eight inches 

 long, which are placed over the shoots on their emergence from the soil 

 and filled with soil. The shoots being ready for cutting, having reached 

 the top of the tube, the tube is lifted off, the soil falls out, and (judging by 

 the illustration) the shoot is pulled away by hand. By this means about 

 a month is gained, as the shoots grow more rapidly. — C. T. D. 



Azolla filiculoides (syn. A. magellanica) (Die Gartenw. 41, 

 p. 483, July 11, 1908). — Introduced from California. The plants 

 resemble miniature Selaginellas, but are aquatic. A. filiculoides is 

 often mistaken for the more common A. caroliniana, but it has larger 

 leaves, and though almost tropical, it survives the most severe continental 

 winters. On the Dutch lakes, ponds, and ditches the plants form a 

 thick covering — at first green, later reddish in colour — to the detriment 

 of other weaker water-weeds. In October or November they decay, 

 leaving the sporangia, which sink, to rise to the surface again in May 

 the following year, and, however few may survive the winter, by July 

 their numbers have increased by millions. They will not grow every- 

 where ; the water must have a muddy bottom with a certain amount of 

 humus and not too much lime. A. caroliniana, an older plant in 

 Europe, increases much slower, and often disappears from places where 

 it may have been at times plentiful. — G. B. 



Bacteriology, Review of Investigations in Soil. By E. B. 



Voorhees and J. G. Lipman (U.S.A. Dep. Agr., Off. of Exp. Stn., Bull. 

 194 ; October 1907). — The matter in this review is itself too condensed to 

 admit of further condensation. It gives an excellent review of the work 

 that has been accomplished during the past few years in the investigation 

 of the part played by bacteria in rendering a soil fertile. The state of 

 our knowledge concerning the action of bacteria in relation to nitrogen 

 and nitrogen compounds is very exhaustively dealt with. — F. J. C. 



Begonia cathayana. By W. B. Hemsley (Bot. Mag. tab. 8202).— 



Nat. ord. Bcyoniaceac. China. Herb 2-3 feet high ; leaves fleshy with 

 soft scurfy crimson hairs; flowers If inch across; male perianth of 

 1 petaloid leaves ; female perianth equally 5-leaved. — G. H. 



Berlin Botanical Garden. By J. G. W. (Gard. Ghron. No. 1117, 

 p. 325, figs. 145 and 146; May 23, 1908; No. 1118, p. 341; and 

 No. 1119, p. 301). — An account is given in this series of articles of the 

 Botanic Garden now being formed at Dahlem, near Berlin. The acreage 

 is said to be only about half that at Kew, and " to be planned on more 

 scientific lines than those which have determined the character of the 

 English establishment." " Something like a quarter of a million pounds 

 (English) have been spent on its construction, and probably at least as 

 much more will be required to complete it. The principal consideration 

 hafl been the provision of a teaching garden." The departments consist 

 of an arboretum, which is the largest and most important, covering 

 ftboui iilty acres; herbaceous and alpine plants; geographical grouping 

 of plants ; medicinal or economic plants ; morphological or biological 



