NOTES AND ABSTRACTS. 
Spray, Combined. By G. A. Meir (Agr. Gaz. N.S.W. vol. xxx. p. 624). — 
Codling moth. Woolly Aphis and Scale are destroyed in one operation by the 
following spray : soft soap, 8 lb. ; tobacco extract, J pint ; lead arsenate, 
4 lb, ; water, 80 gallons. — S. E. W. 
Spray Gun. By W. J. Allen {Agr. Gaz. N.S.W. vol. xxx. pp. 893-894. 
Comparative tests have proved that ordinary spraying is more effectual and 
cheaper than spraying with the gun. — S. E. W. 
Spray Gun versus Rod and Dust in Apple Orchard Pest Control. By L. Childs 
{U.S.A. Exp. Stn. Oregon, Bull. 171, July 1920, pp. 5-46 ; 17 figs.). — The results 
of four years' experiments, 1916-1919, in dusting are described and tabulated. 
Scab and codling moth have been controlled by dusting — spray rods and guns 
giving almost identical results. 3^ to 4 h.p. sprayers can only efficiently operate 
one gun at a pressure of 250 lb. Costs have been worked out of the difference 
between 3I and 10 h.p. machines, and it was found that with the lesser horse 
power the work could be done slightly cheaper, but not so economically or 
efficiently as with the higher horse-power machine. — G. F. W. 
Sprays Mixed. By A. A. Ramsay {Agr. Gaz. N.S.W. vol. xxx. pp. 428, 
429 ; I fig.) — Emulsified oils cannot as a rule be mixed with other spraying 
materials. Ferrous sulphate and sulphuric acid must be used alone. The 
following mixtures are permissible ; 
Liver of sulphur with soap, washing soda. 
Ammonia copper carbonate with tobacco extract. 
Bordeaux mixture with lead arsenate, Paris green, tobacco extract. 
Burgundy mixture with tobacco extract. 
Iron sulphide with Bordeaux, lime-sulphur. 
Lead arsenate with Bordeaux, lime-sulphur, atomic sulphur, tobacco extract. 
Lime-sulphur with iron sulphide, lead arsenate, tobacco extract. 
Paris green with Bordeaux, tobacco extract. 
Resin wash with kerosine emulsion, tobacco extract. 
Soap with alkali sulphides, Bordeaux, tobacco, resin wash, washing soda. 
Sulphur (atomic) with lead arsenate, Paris green. 
Tobacco extracts with ammonia copper carbonate, Bordeaux, Burgundy, 
lead arsenate, lime-sulphur, oil emulsions, resin wash, soap, washing 
soda. 
Washing soda with alkali sulphides, emulsified oils, soap, tobacco extract. 
5. E. W. 
Stanhopea costaricensis Reichb. f. By R. A. Rolfe {Bot. Mag. t, 8830 ; 
March 1920). — A species collected by Mr, C, H. Lankester in Costa Rica and 
flowered at Kew has been identified tentatively with Reichenbach's Stan- 
hopea costaricensis. The flowers are large with buff -yellow sepals, marked 
with light-red somewhat ring-like spots, and with smaller spots on the petals 
and lip. The lip possesses a curious sac and there are two dark-red " eye " 
spots on the lip. — F. J. C. 
Steam Sterilization. By E. G, Beinhart {U.S. Dep. Agr., Farmers' Bull. 
996, pp. 1-15; 4 figs.). — In raising Tobacco plants from seed, it is a great 
advantage to sterilize the seed-beds as a protection from fungoid diseases. This 
is best accomplished by the steam-pan process. The steam-pan is an inverted 
shallow wooden box, 4 inches in depth, wide enough to fit in the sides of the 
frame of the seed-bed, e.g. 12 ft. by 6 ft. It is connected by a hose with a 
20-h.p. boiler, and the pressure in the boiler must be maintained at 100 lb. 
After thirty minutes, the steam is shut off and the pan moved along the bed to 
the next area. The steamed area is covered with a blanket to conserve the heat. 
The seed-bed before steaming must be well worked, the fertilizers mixed in the 
soil, and the whole comparatively dry. The seeds may be sown twelve hours 
after the steaming. — 5. E. W. 
Stomata, Influence of Light upon the Action of. By J. Gray and Geo. J. 
Peirce {Amer. Jour. Bot. vol. vi. No. 4, April 1919, pp. 131-154 ; 18 figs.). — The 
study of the stomatal reactions of various cultivated and wild species by the 
authors have led to the following conclusions : 
(i) The stomata of barley, wheat, oats, and rye plants open ^vith licht 
and close with darkness. (2) Increase or decrease in the amount of light, when 
it has reached a minimum intensity, will have a corresponding effect upon the 
width of the stomatal openings. (3) The opening and closing being accomplished 
by the changes in shape of the guard cells of the stomata, a minimum amount 
