NOTES AND ABSTRACTS. 
429 
Sigmatostalix costaricensis Rolfe {Bof. Mag. t. 8825 ; Dec. 1919). — A 
species from the Andes flowered at Kew in October 1915, producing a spike of 
small green, red, and yellow flowers, and thriving with the Oncidiums. — F. J. C. 
Sinapis Juncea var. napiformis. By R. de Noter {Le Jard. vol. xxxiv. 
pp. 157, 158 ; I fig.)- — -The tuberous Chinese Mustard [Sinapis napiformis) 
provides a useful culinary root resembling a turnip in shape. It can be raised 
from seed. — S. E. W. 
Snapdragon Rust. By Geo. L. Peltier {U.S.A. Agr. Exp. Stn. III., Bull. 221, 
Aug. 1 91 9, pp. 534-548). — The rust of the snapdragon {Puccinia Antirrhini 
D. & H.) has been known since 1879 in California, but it is only in recent years 
that it has made an appearance in Illinois. The disease attacks plants in all 
stages of growth, and becomes evident on leaves, pods, and stems, both outdoor 
and under-glass plants being affected. The fungus appears to be limited to the 
snapdragon {Antirrhinum majus Linn.) and its varieties, all of which are equally 
susceptible. Bordeaux and other spraying fluids are not effective in controlling 
the disease. The best control measures are attention to cultural methods, the 
destruction of all affected plants, and avoidance of excessive moisture. — A. B. 
Snow Flies. By W. W. Froggatt {Agr. Gaz. N.S.W. vol. xxix. pp. 434-436; 
I plate). — The Snow Fhes {Aleurodidae) are related to the scale insects and to 
the plant lice. The plump body and the two pairs of rounded wings are covered 
with white mealy dust. Infested foliage appears to be covered with spots. 
A new species. Aleurodes alhofloccosa, is 4 mm. in length; the white hair, like 
filaments springing from the margin of the test, measure from J inch to \ inch 
in length.— 5. E. W. 
Soil Solubilities, Rate and Extent of. By Geo. J. Bouyoucos {U.S.A. 
Exp. Stn. Mich., Tech. Bull. No. 44, June 1919, pp. 1-50). — The study of 
the rate and solubility of soils is obviously of great importance from both a 
practical and scientific standpoint. The questions of the velocity and amount 
of soil passing into solution, the application of the mass law, the solubility law, 
the difference in rate and extent of solubility under- various treatments and 
state of fertility are of fundamental importance. The author in the investiga- 
tion of the problems made use of a new method — the freezing-point method. The 
soils were washed to remove all the free-soluble salts until they had a freezing- 
point depression very close to that of distilled water. The rate and extent 
of soil solubility at various moisture contents were measured at different tem- 
peratures : (i) below freezing ; (2) 20°C. (room temperature) ; (3) 53°C. Seven 
different soils] were employed in this study : one clay, two clay loams, two 
silt loams, one sandy loam, one sand. When 'different soils were treated with 
N/io Ca(NOj)2, NaNOa, KNO3, KCl, KgSO/, (NHJ^SO^. MgSO^, KH.POi, 
CaH4(P04)2, and NaC.^HaOg, and then washed until all their free-soluble "salts 
were eliminated and their water-content consisted of i of soil to -7 of water it 
was found that at room temperature the rate of solubility was slow and gradual ; 
and this continued for 50 to 120 days, except in the case of (NH4)2S04, where 
the rate was very rapid at the beginning, but it soon slowed down. The extent 
of solubility or the amount of material which dissolved was appreciable. The 
concentration of the soil solution depends upon the relative masses of the soil 
and water. The amount of material that goes into solution seems to increase as 
the ratio of soil to water is increased up to about the optimum moisture content, 
and then it decreases. — A. B. 
Soil, The Destruction of Vanillin by Soil Bacteria in the. By William 
J. Robbins and A. E. Elizando {U.S.A. Exp. Stn. Alabama, Bull. 204, 
June 1 91 8, pp. 124-132). — The author in a previous paper ha? shown that the 
absence of toxic effects of a toxic organic compound added to soil depends 
upon the presence and action of suitable micro-organisms which destroy the 
toxic compound. In this paper it is shown that vanillin (an aldehyde which 
is harmful in water culture at a concentration of one part per million to wheat 
plants) is rapidly destroyed by the action of bacteria. These bacteria have 
no bad effect upon the growth of plants. — A . B. 
Soil, The Nitrification of Pyridine, Quinoline, Guanldine Carbonate, «&c., in. 
By M. J. Funchess {U.S.A. Exp. Stn. Alabama, Bull. 196, June 1917, 
pp. 65-82). — The following summary is given of the conclusions arrived at : 
Quinoline is nitrified most readily in soil with highest lime requirement. 
Lime retarded or inhibited the nitrification of quinoline ; it also inhibits nitri- 
