586 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



water which a soil will retain when in equilibrium with a definite force. 

 The soil is first thoroughly moistened and then placed in the perforated cups 

 of a centrifugal machine, where it is subjected to a constant centrifugal 

 force until it ceases to lose water. The percentage of water remaining 

 is then determined. By this means is ascertained the moisture contents 

 which soils must have in order to make it equally difficult to remove 

 a very small additional amount of moisture from any of the soils. 

 Thus, using a centrifugal force equal to 3,000 times the force of gravity, 

 it was found that the moisture equivalents varied from 3*G per cent, 

 in the coarser sandy soils to 46*5 per cent, in the heavy clay subsoils. 

 For this force organic matter has a retentive power no greater than 

 that of clay. — F. J. C. 



Mussaenda erythrophylla. By W. B. Hemsley (Bot. Mag. 

 tab. 8222). — Nat. ord. Bubiaceae ; tribe Mussaendeae. Tropical Africa. 

 Shrub to 40 feet high ; leaves 6-7 inches long ; calyx-lobes all ^-J inch 

 long, or one, leaf-like, 5 inches long by 4 inches broad, brilliant crimson ; 

 corolla salver-shaped, 1 inch in diameter, yellow or rose. — G. H. 



Odontogrossum Cervantesii, Abnormal. By H. Hus (Rep. 

 Miss. Bot. Gard. 1907, pp. 95-97 ; 1 plate). — A description of several 

 flowers, abnormal in the number of floral leaves and anthers produced, 

 and in the presence of colour in the column, produced by the same plant 

 in successive seasons. — G. S. B. 



Olive Tubercle Organism, Recent Studies of the. By E. F. 



Smith (U.S.A. Dep. Agr., Bur. PL Lid,, Bull. 131, Part IV.; August 

 1908). — This disease, prevalent in California, causes swellings on the 

 branches of olive. The swellings are the result of the attack of a 

 bacillus, and this paper gives an account of the studies carried out upon 

 the organism. He considers it best to coin a new name for the organism 

 on account of the confusion surrounding the present names, and proposes 

 Bacillus Savastanoi (syn. B. oleae tuberculosis). A careful diagnosis and 

 account of cultural characteristics is given, and an account of infection 

 experiments. The author is unable to confirm the conclusion reached by 

 C. O. Smith that this organism is the cause of the tubercle of oleander. 

 The latter he believes to be caused by B. tumaefaciens (see "Crown- 

 gall"). B. Savastanoi does not produce tubercles on Chrysanthemum 

 frutescens. — F. J. C. 



Orchid Portraits. — The following orchids have been figured 



recently : — 



*Brasso-Cattleya Cliftonii . . Gard. Mag. 1908, p. 943. 

 *B. Madame Hye .... 

 *B. Queen Alexandra, Glenthorne 



var. . . 

 Bulbophyllum galbinum . . Bot. Mag. t. 8216. 

 *Calanthe x Angela 

 *Calanthe x Norman . 

 Catasetum Claesianum . . . Gard. Chron. 1908, ii. p. 211, 



fig. 90. 



