we ll 
trade and to the user, what we consider good makes. The largest 
sale is for knapsack sprayers, which are being more widely used, 
but spraying is restricted. 
FUMIGATION is not practised in India for either buildings or 
plants, but there is a limited amount done for grain, using carbon 
bisulphide. It is never likely to be widely used inland on account 
of the cost, the damage ofthe material and the immense cost of 
carriage by rail. The treatment of grain and seeds stored in bulk 
against Weevil, etc., will be on other lines, not using fumigants at 
all probably, and we have sought to replace carbon bisulphide 
by some other fumigant in industrial use such as for factories, etc. 
Some such liquid as carbon tetrachloride will probably be used. 
Fumigation of plants and buildings with hydrocyanic acid and of 
grain with carbon bisulphide is practised at Pusa, and if there is 
scope for it, will be adopted more widely. 
A distinct branch is concerned with Insects that affect the health 
of man and his domestic Animals; the Insects parasitic on Animals, 
the Insects that are known to convey disease, the Insects which 
suck blood and which are possible disease-transmitters, are being 
studied and worked at; this work is in its infancy; but it has 
reached the stage where we know what the more common blood- 
suckers and parasitic Insects are, and for a number of them have 
worked out life-histories and know their habits. The difficulties of 
the Mosquito problem in India are well known, and in view of the 
impossibility of using ordinary insecticidal remedies in any but a 
very small minority of cases, many of the difficulties with Cattle- 
pests are much increased. It is probable that progress with this 
branch of entomology will have to be made on different lines 
from those on which the treatment of crop pests has gone, and 
that when the initial work has been completed, it will be found 
that only by further investigation on more purely physiological 
lines will it be possible to make more than a slow advance in 
certain directions. 
Few countries suffer a greater loss of potential energy from 
Insect attacks than does India from the almost universal preva- 
lence of Mosquito-borne malaria, and in this one direction alone, 
in spite of the good work that has been done by many medical 
officers, there is ample scope for detailed bionomic research of a 
kind which might have far-reaching results. 
The work at Pusa is carried on in connection with the Medical 
