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THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY. [V, I
the usual period after infection, which later developed the disease on the lowering
of their vitality. Edwards [1928] detected the virus in a sheep up to one month,
but the longest time was not determined. In Delpi's [1928-30] atypical cases amongst
cattle, the blood was infective through the entire period of 1½ months.
3. In regard to the introduction of rinderpest into Belgium through the Indian
zebus en route to Brazil, the idea of the disease being kept up by cases occurring
in series during the voyage is the same as Stockman's " smouldering in a densely
stocked location", but this view does not seem to be of much practical value to the
point at issue here, since it would be very strange that out of the whole consign-
ment not a single animal was reported to have exhibited any distinct symptoms,
when seven of them were to die later, soon after landing. Further if this theory
were correct, it seems probable that cases of death, if they should occur, would
have been in series rather than almost simultaneously, as actually happened at
Antwerp. Moreover when death did take place, rinderpest was not even suspected.
This could not have been so, if they were cases of the acute type, since the lesions
of acute rinderpest at autopsy, being quite well-known to veterinarians, could
not have escaped the notice of the quarantine authorities.
4. (A) In regard to Delpi's cases, the food and water supply cannot be incrimi-
nated, in view of the extreme fragility of the virus under natural conditions and
on dilution, and because the forage must have been obtained from a stack rather
than from sources where there might be a possibility of accidental contamination
with infected excreta.
(B) The outbreak of rinderpest in the island in question cannot be explained
on the hypothesis that the calves arrived there in the recovery stage, since animals
recovering from the acute disease are known to be non-infective.
(C) Delpi's own assurance that the disease did not exist there previously settles
this conjecture.
5. It seems that the words ' reaction' and ' reacted ' have been used wrongly
in this paragraph in the sense of ' infection ' and ' infected '. Contrary to the
view of Mr. Purvis, it seems to us that Schern's statement, concerning the failure
of only 34 out of a total of 131 animals inoculated with the virus to exhibit symp-
toms, can have only one meaning, viz., that the balance of 97 did react.
It is certainly extraordinary to hypothesise that the inoculation of virulent
blood may not cause infection in susceptible cattle. One knows that (depending
upon the degree of susceptibility) susceptible animals, when inoculated, run one of
the three courses, viz., (i) develop the symptoms of the disease in the acute form,
ending in death in most cases, (ii) develop a thermal reaction only without the
exhibition of any other visible symptoms, (iii) develop neither clinical symptom,
nor a thermal reaction, though the presence of the virus in the blood can be never-
theless revealed by animal inoculation. The survivors are in any case immune
to a subsequent infection. In fact the final proof of the viability of the virus at the
initial inoculation is obtained by testing animals for immunity with a second ' test