162     INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ III, II

the total dose of cercariæ swallowed would be about 15,630, in addition to what
might burrow through the skin. Though in the natural mode of infection these
animals might get comparatively larger doses than it is possible to give under
experimental conditions, yet it would appear that Nasal Schistosomiasis can be
produced in calves with comparatively smaller doses of cercariæ.

On the 3rd day of infection in the nose, the muffle of calves Nos. 409 and 411
showed dryness, the edges showed scaling of the epithelium and the mucous
membrane too was reddened with small red dots on it. These symptoms disappeared
in about a week after the first course of application of cercariæ. Similar symptoms
were again noticed during the second course of application of cercariæ to the nose.
The nasal washings and fæces of the three calves were periodically examined from
the last week of January 1933. From about the 15th February calves Nos. 409 and
411 showed a thin discharge from the nose and occasional sneezing was observed in the
latter. On 28th February 1933 a few small beads of pus were seen in the nostrils
of calf No. 411 and when the discharge was examined, it showed ova resembling
those found in nasal schistosomiasis and all of them contained live miracidia. On
3rd March 1933 calf No. 409 also showed suppurative foci on the mucous membrane
of the nose, and on 4th March 1933 ova were seen in the nasal discharge as in the
other. This experiment shows that the minimum period of incubation in the two
calves is roughly 3 months. Calf No. 410 has been showing a discharge from the
nose but no ova have been found in it up to the time of writing this paper. So far
none of the calves showed ova of S. spindalis in their fæces.

It is my pleasant duty to acknowledge my indebtedness to Mr. T. J. Hurley,
M.R.C.V.S., D.V.S.M., Principal, Madras Veterinary College, for the valuable
suggestion of infecting one calf in the nose only and the calf infected in this way
has shown the disease first. I am also grateful to Mr. P. T. Saunders, O.B.E.,
M.R.C.V.S., Director of Veterinary Services, Madras, for obtaining sanction to
conduct these experiments, and to Messrs. A. Ramaswamy Ayyar, K. P. Dorai-
swamy, L. S. Parameswara Ayyar and S. Vaidynatha Mudaliar for all the help
rendered by them in this work. My thanks are also due to Mr. R. Narasinga Rao,
District Veterinary Officer, Madras, for providing me with snails from Conjeevaram
on two occasions.