THE CURRANT BUD-MITE. OR CURRANT GALL-MITE. 299 
bushes planted out in the field. Forty minutes of 0*15 gramme to 0'2 
gramme cyanide per cubic foot was eft'ectual in destroying every mite in 
large bushes severely infested with the pest. . . . The months of 
December and January appear to be the best months for fumigation, 
owing to the absence of eggs at the season." The discrepancies between 
the results obtained at Woburn and Wye are therefore most marked. I 
should add that we have yet to learn from Wye what effect the gas has had 
upon the eggs, as I have had abundant proof that these do occur in 
December and January in spite of what has been said to the contrary, and 
unless these were killed by the same treatment we must expect a recurrence 
of the disease. Moreover I believe, from a report which appeared in the 
Standard for May 1, 1900, that the experiment on the large growing bushes 
was not an established success.* 
Further experiments with the hydrocyanic acid gas have recently been 
carried out both at Woburn and at Wye. And Mr. Wise is also giving 
the treatment a trial at Toddington. The results at Woburn and 
Toddington have, so far, proved successful, but nothing definite can be 
known with regard to the ultimate success of the treatment until the 
season has advanced. 
The following rules should be observed with regard to the gas treat- 
ment of infected bushes, which, in the main, apply equally to any other 
method which may be adopted : — 
(1) Cyanide of potassium is a deadly poison and should only be 
used by a responsible person. 
(2) If a few plants only are to be experimented on, they should be 
removed from the soil and treated in an air-tight chamber, or as 
recommended in the Wye College Eeport (see p. 303). Immediately 
afterwards they should be removed and transplanted to a distance of 
not less than half a mile from the infected area. 
(3) The application of gas to a selected number of plants in an 
infected plot would prove absolutely useless. When the treatment 
is to be adopted on a large plot of growing plants every plant in the 
plot should receive uniform treatment throughout. 
(4) Make the application at least twice — the first about the end 
of January, the second fourteen to twenty days later. 
As to the methods of prevention, these consist of — 
(1) A clean healthy stock to begin with. 
(2) Planting in single rows between other crops, or in small 
isolated plots. 
(3) Prune so as to admit plenty of light and air. 
(4) Above all, keep an ever watchful eye for the first signs of 
the disease, and burn the first bushes which show the least sign 
of it. 
In conclusion I beg to tender my sincere thanks to Miss Ormerod, 
LL.D., to Mr. Spencer Pickering, F.K.S., Director of his Grace the Duke 
of Bedford's fruit farm at Woburn, and also to Mr. Lewis Castle, the 
Manager, for giving me the valued opportunity of helping in the Woburn 
* Mr. E. J. Lewis, Agricultural College, Wye, informs me, " The bushes were as bad 
as ever in the following autumn." In lit. 6, ii. 1900. 
