358 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [III, IV.

The present note records the results of transmission experiments carried out
upon only five dogs, two of which died from causes other than P. gibsoni infection,
whilst the remaining three duly developed the infection. In view of the small
number of experiments carried out and of the fact that no special precaution was
adopted to prevent the animals from contracting a natural infection, the results
reported in this note must be regarded as of a tentative character until further work
has been done, under more controlled conditions, to confirm these findings.

The writer desires to acknowledge his grateful thanks to Mr. F. Ware,
F.R.C.V.S., I.V.S., Director of the Imperial Institute of Veterinary Research,
Muktesar, for his kind encouragement and for granting every facility in the
prosecution of this investigation.

                                 FEEDING OF TICKS ON DOGS.

At the outset it was realized that one of the fundamental difficulties
that hampered the progress of investigations of this kind was the lack of a
suitable method of feeding ticks (particularly the larval forms) on dogs. Patton
(l. c.) and Rao (l. c.) have not indicated the methods adopted by them in feeding
their ticks, but Rao mentions having recovered 30 nymphs in one instance, 20 in
another and 30 in a third, and from this one would gather that the number of
nymphs which he failed to recover was not small, for ticks, as a rule, bring forth
a considerable progeny.

In his work on the transmission of malignant jaundice of dogs through the
agency of R. sanguineus, Christophers [1907] enclosed his experimental animals
(" pups of medium size" ) in cages of iron which were kept surrounded with sheets of
muslin to enable any engorged ticks to be readily seen and collected. A similar
type of cage is also recommended by Patton and Cragg [1913] for feeding
R. sanguineus, the cage being provided underneath with a tray to catch the
urine or faeces of the enclosed animal. The ticks to be fed are dropped upon a
quantity of straw placed inside the cage, care being taken first to remove the
underpan in order to avoid any of the ticks getting drowned in the urine which may
have collected in it. The dog is taken outside when required to feed and
the cage is cleaned once a day by removing all faeces, urine and soiled straw, whilst
the removal of such ticks as have lodged themselves between the bars of the cage
is effected by bumping the cage over a piece of white cloth placed upon the
floor.

In his work upon the life-history of R. sanguineus, Nuttall [ 1913-14] enclosed
his dogs in a barrel-shaped metal cage " placed horizontally upon an insulated- stand,
one end of the barrel being open but guarded by a metal grating, a similar grating
serving as a floor for the animal to stand upon ". The" cage was searched daily,