R. L. KAURA and S. GANAPATHY IYER                         201

Material from the buccal lesions has not been used for subinoculation
purpose because it has been established in another paper by the authors [1936]
that in an identical condition in Indian fowls the causal agent of the buccal
diphtheritic lesions and the cutaneous lesions is one and the same filterable
virus.

                TRANSMISSION EXPERIMENTS

(a) Experimental transmission of the disease in pigeons.—Five apparently
healthy pigeons that were in contact with the natural cases of pigeon-pox
were soon separated and inoculated on 20th April 1936 with the Indian
strain of pigeon-pox virus as a preliminary experiment (Table I). It
took some weeks before a fresh lot of healthy pigeons could be obtained.
Pox lesions devloped only in Pigeon No. 3 and the remaining four pigeons
resisted the infection bably due to the varying degree of immunity which
might have developed area result of their having been in contact with the
naturally infected cases before they were segregated or due to their being
naturally immune to this infection as considered by Findlay [1930].

Three weeks after the above experiment, Indian strain of this virus after
passage through Pigeon No. 3 was subinoculated into five healthy pigeons
on 12th May 1936. Of these, four readily took the infection and in one
(Pigeon No. 45) there was no reaction (Table I).

Mixed crusts from Pigeons Nos. 41, 42, 43 and 44 were further passaged
into twelve healthy pigeons on 13th June 1936 with the result that experi-
mental disease was reproduced in ten pigeons and two were found to be re-
sistant (Table I). Subsequent passages of the Indian strain of this virus
were continued in pigeons for the availability of the material for further
work.

Lesions in the experimentally infected pigeons were mostly confined to
the seat of inoculation. Some of these birds developed acute gastro-enteritis
and succumbed and one showed eye lesions as well.

                                          TABLE I

         Experimental transmission of the disease in pigeons