[FLETCHER | PRESIDENTIAL ADDRESS 9 
country than has ever been previously the case over an equal area of ter- 
ritory, and during the present spring there is certainly an enormous 
increase in the number of fruit-growers and farmers who are adopting 
this useful method of protecting their crops from injury. This is to a 
large measure due to an excellent series of experiments carried on by my 
colleague, Mr. John Craig, Horticulturist of the Central Experimental 
Farm, in the fruit orchards of western Ontario last year. I have 
no doubt at all that the fruit-growers of Canada will reap a rich 
harvest for their pains, which will much more than repay them for 
the extra outlay and labour. The question of the combination of 
fungicides and insecticides, first prominently brought forward by Prof. 
Clarence M. Weed of New Hampshire, is now known to be an important 
one, and many of the agricultural experiment stations have issued spray- 
ing calendars in which this dual treatment is universally recommended. 
2. Kerosene emulsion, the standard remedy for Sucking insects, is 
simply an emulsion made by churning for five minutes two gallons of coal 
oil with one gallon of hot soap-suds containing half a pound of soap. This 
gives the stock emulsion, which may be reduced with water to any 
degree of weakness, and which may be used on most foliage with im- 
punity, if mixed with nine times its volume of water. Moreover, it is a 
most effective destroyer of all insects upon which it may be sprayed. It 
is particularly effective against scale insects, a class of insects which are 
very difficult to treat. In the effort to eradicate the pernicious San José 
scale, recently detected in the eastern States, this was found to be a use- 
ful remedy. The occurrence of that scale east of California, and the 
vigorous, prompt measures adopted by the United States Entomologist, 
have obtained for that ofticer great credit among the fruit-growers of 
America. 
Another of Mr. Howard’s triumphs was the working out of the full 
life-history of the Cattle Horn-fly, a pest of horned stock, which of 
recent years has been the cause of much loss to dairymen. I happened 
to be in Washington at the time its first occurrence was announced in 
Virginia, and had the opportunity of going with Mr. Howard to the 
infested district, where he collected the first eggs of the fly, from which 
he successfully worked out the complete life-history, and proved that 
the maggots bred entirely and only in fresh cattle droppings. This 
indicated at once two remedies : one preventive, for protecting the cattle 
from the bites of the flies, for which kerosene emulsion, with a little car- 
bolic acid added, is one of the best; and the treatment of the droppings 
so as to render them unfit breeding-places for the maggots. 
CONTROLLING BY NATURAL ENEMIES. 
One of the most remarkable instances of widespread benefit to a 
large district from the carefully thought-out plans of a competent ento- 
mologist is the celebrated case of the introduction into California by 
