20 Geonjlva Sweet : 



certainly show some slight indication of a not very distant common 

 ancestry, and there is no doubt in my mind that the host animal 

 of the original Asiatic nodule-worm will yet be found in the Indo- 

 Malayan gaur or wild ox (Bos (Bibos) gaurus), or its variety, the 

 Seladang, or the nearly allied species, the Javan Bantiri. 



It is to be noted further that in the regions where these nodules 

 occur in Australia, the number of animals affected is much greater 

 than in similar parts of India and apparently of Malaya. This 

 greater frequency in Bos taurus is undoubtedly due to its having 

 less resistance to the development of the parasite than has Bos 

 indicus, which is at least more closely allied to the presumptive 

 original host. As to Java, I have been unable to obtain definite 

 information as to the relative frequency of the nodules in introduced 

 or locally bred Bos taurus or Bos indicus. 1 One is justified in the 

 light of the evidence in expecting to find in Javan nodules character- 

 istics closely similar to those of the Australian form, though whether 

 they have been introduced into Java from Malaya or from India, is 

 as yet unknown, though one would judge the former to be the more 

 probable. It is, of course, quite probable if the In-do-Malayan gaur 

 were the original source of infection that also the Seladang of 

 Malaya was and is likewise infected, and that this was the imme- 

 diate source of the infection of the Malayan cattle. Whether the 

 Javan Bantin was also infected, either originally or secondarily, or 

 whether the infection came there from the Malay Seladang or from 

 Malay cattle, we cannot yet tell. 



The greater variability of the Australian form is only analogous 

 to what I have pointed out previously (vide supra), that the ten- 

 dency is when parasites are introduced into this continent, even 

 in their normal European (or other) domesticated host, for con- 

 siderable variation to take place at times resulting in the forma- 

 tion of what appears to be a distinct and new species. 



It is greatly to be regretted that material is not yet forthcoming 

 from the Malay Archipelago for close comparison with these forms. 

 as it would appear from the above that the entrance of the nodule- 

 worm into Australia cannot be credited to the introduction of 

 Indian cattle into the Northern Territory, but rather to that of 

 cattle from further East, and so quite probably from Timor — as 

 previously emphasised— sometime between 1824 and 1840. It is to 

 hoped that information and material from Timor may soon be 

 forthcoming, in which one may expect to find a link between the 

 Malayan and the Australian 0. gibsoni. 



1 See Addendum 2. 



