: 
maturity appear to possess a greater resistance against the disease. 
These statements do not seem to us to be strictly applicable to cattle in 
the Philippine Islands. Our experience has taught us that calves are 
satisfactory subjects for immunization, that milch cows or pregnant 
animals are less so, and that maturity plays no part in susceptibility. 
Sex has no influence, if the physical condition of the animal is normal. 
Natural resistance, immunity, and susceptibility—Rinderpest is a 
disease of cattle and of some allied ruminants. 
Man is immune, as are cats, dogs, donkeys, rabbits, guinea pigs, rats, mice, 
doves, hens, eagles, flamingoes, ete. (Koch, Nicolle and Adil-Bey, Tokishiga, and 
Tartakowsky.) Sheep and goats are not completely immune, but they have a 
natural resistance to the disease. However, in these animals as -in others, there 
are yacial differences. Both species may show a rise of temperature after experi- 
mental inoculation and if the blood is drawn at this time and used to inoculate 
non-immune cattle, the disease may be produced. (Kolle and Turner, Koch, Theiler 
and Pitchford, Woronzow.) Sheep may be the means of spreading contagion as 
Koch and Rogers have stated. . 7 
Hogs, camels, antelopes and buffaloes are not so highly susceptible though 
any of these may have the natural or artificial disease. 
Natural infection of hogs has been reported from Tonkin and Annam by 
Clive and Fraimbault. Tartakowsky, in opposition to Refik-Bey, states that 
camels are sensitive in a certain degree, but that they usually resist the disease 
or only show mild symptoms. Mense, from his observations, concludes it to be 
possible that buffaloes may die in large numbers, though Nencki and his fellow- 
workers say that they are less susceptible than cattle. However, there is not 
only the difference in immunity of species but there are racial differences of 
susceptibility and resistance. 
In India, Rogers and Lingard found the hill cattle so susceptible that the 
usual methods of immunization used in the case of animals from the plains were 
of little avail with the former. These differences, as Sobernheim suggests, may 
be a result of the endemic occurrence of the disease which, in the course of time, 
has given rise to incomplete resistance but not to an inborn racial immunity. 
Kolle has observed in the Soudan, and Pinching and Bitter in Egypt. that the 
cattle of those localities have a very slight, whereas those of South Africa have a 
uniform susceptibility. 
In the Philippines the variation is so great that, save in a few islands, 
it can not in advance be stated without further experimental evidence, 
whether the cattle are susceptible or not. In the Babuyanes group and 
in Sibuyan, rinderpest has never been experienced, but nevertheless 
there is an apparent relative resistance to infection in the cattle from 
these places. The same is true of the animals from certain parts of 
Australia. The susceptibility of American stock seems to be very great. 
We have had a very bitter experience with such animals and have found 
the usual methods of immunization, which are perfectly safe with Phil- 
ippine cattle, to be extremely dangerous when applied to the former. 
In this Bureau we have performed some experimental work in the 
study of the immunity or susceptibility of laboratory animals. 
