OBSERVATIONS ON DOYLE'S DISEASE OF FOWLS                325

and fourteen fowls were protected with trypanblue solution at the rate of 1 to 3
c.c. according to age. The drug was injected intravenously in some and sub-
cutaneously in others. All fowls were allowed to move about as usual and re-
main in their own pens. Only one of these birds showed symptoms of the disease
on the 7th day after injection, which was thereupon destroyed and burnt. All
other birds remained perfectly healthy. Details of these fowls are given in Table
II.

The results obtained in this experiment show that trypanblue afforded ade-
quate protection to fowls subjected to its injection and maintained under field
conditions.

Experiment 3.—A similar experiment as the one preceding was undertaken
at the village Bori, in Poona District. The disease had broken out there on 7th
January 1936 and there were 123 attacks, 115 deaths and 8 " still affected ".
Fifty fowls which were apparently healthy were protected with trypanblue at the
doses mentioned already, in the affected locality and were allowed to remain
under natural conditions. Affected fowls were neither isolated nor destroyed
although owners were advised to do so. Amongst the fowls protected, three died
of the disease : one on the third day and two within a course of a week.
All others failed to contract the disease while, it is reported, that about 50 un-
protected fowls died subsequent to the prophylactic injections carried out in the
village. Details of the protected fowls are given in Table II.

These results show that 94 per cent of the fowls protected with trypanblue
failed to contract the infection of the disease under field conditions.

Experiment 4.—While I was carrying out experiment 1 at Kedgaon, Rev.
J. E. Norton, B. C. H. Mission, Dhond, personally requested me to save the fowls
of the Mission workers at Dhond from the jaws of this disease which was pre-
valent there since 14th January 1936. Two hundred and twenty-four fowls
had already died of the disease and there were six affected. Reserve Veterinary
Assistant Surgeon, Nemade, who was attached to my office temporarily was de-
puted there, who injected 142 fowls which were apparently healthy with the same
dose of trypanblue as stated in the previous pages. They were allowed to move
about as usual and to remain under the same field conditions as they were before.
I checked the results 51 days after and found that the disease had subsided about
9 days after the injection and that 29 fowls from the protected lot had died of
the disease ; 13 died within 5 days, 15 showed dullness from the second day
after injection and died within a course of a week and 1 died on the 8th day.
Details of these birds are given in Table II.

These results show that the percentage mortality among the birds protected
is 20.4. But, it would appear, by a close study of these fowls and referring to
Table II that out of the 29 fowls 28 were in the incubation stage of the disease
at the time of injection. For, in experiment 1, it has been seen that the minimum