16 J. A. Gilriiih: 



tick fever. Had its presence been overlooked in any instance, one is 

 safe in cnnclndinf!: that it would have been heard of primarily in one of 

 the southern districts. But we hear of its appearance first in the 

 northern parts of the tropical regions, far away from known ports of 

 cattle entr}^. 



One is therefore impelled to the conclusion that the disease must 

 have entered by way of the northern littoral, unless indeed it be 

 assumed that the same tick parasite affects indigenously the native 

 fauna, for which assumption there is absolutely no evidence. Irresist- 

 ibly we are compelled to look to the countries lying north of Australia 

 as the possible source of original infection. 



The nearest territory whereon cattle are husbanded is the Dutch 

 Indies. There we know that the tick is a common parasite among the 

 native cattle, and that although these cattle exhibit a great natural 

 immunity to the blood-parasite {Babesia), the true cause of tick fever, 

 which is transmdtted by the tick, yet imported non-immune cattle 

 are very susceptible, at least in the Straits Settlements adjacent, 

 and unless special precautions are adopted, are almost certain to 

 succumb in considerable numbers. The same conditions obtain in 

 other tropical countries lying farther north. 



Our nearest neighbour has, therefore, this tropical disease of cattle. 

 But we are separated from her by hundreds of miles of sea, communi- 

 cation is infrequeni, and besides, there are no official records of the 

 importation of cattle therefrom to Australia. If it can be shown that 

 live cattle have been imported notwithstanding, the position becomes 

 clear. If not, it seems obvious that other agencies must be looked for, 

 and that if this disease has been introduced by unknown means, other 

 and perhaps more to be dreaded tropical animal maladies may be 

 introduced in the future ; indeed, they may be at the present moment 

 existing to some extent in our northern areas. 



The buffalo naturally oft'ered a possible solution. It is well known 

 that the Governors of the British settlements at Melville Island and 

 Port Essington (aj)out 1826 and 182(S) imported the mud or swamp- 

 buffalo from Timor, and Johnston and Cleland have drawn attention 

 to the fact that the Governor of the Port Essington settlement was 

 also empoweied to import cattle from the Netherlands Indies, though 

 they could find no rtMord of this having been done. 



Since their introduction to Port Dundas by Sir Gordon Bremnier in 

 1824, the buffalo have spread all over Melville Island ; and since their 

 introduction to the mainland at Port Essington they have gradually 

 spread southward along the swampy plains near the sea-coast to within 

 a few miles of Port Darwin. A few have wandered inland, hut chiefiy 

 bulls Avhich have left the main herds, one or two being occasionally 

 seen as far as the Roper and even the McArthur Rivers. 



