PRESIDENTIAL ADDRESS. 1 1 



Already we know of a considerable number of tropical 

 diseases in Australia, such as malaria, tropical dysentery, 

 filariasis, ankylostomiasis, yaws, beri beri, dengue, Gulf 

 fever ; but there are said to be other diseases not under- 

 stood, not recognised, that require to be studied. In any 

 case, the age of fast steamers may bring various kinds of 

 undesirable immigrants, including diseases from other lands, 

 against which we need to be protected by knowledge of 

 the subject, so that we may employ the best preventive 

 and hygienic measures. 



From the accounts given by my friends, Dr. F. J. Mac- 

 Donald, of Geraldton, and Dr. Peter Bancroft, of Brisbane, 

 ankylostomiasis, or the earth eating disease, or leech worm 

 disease Dr. MacDonald calls it, is very widely spread in 

 North Queensland, far more so than is generally supposed, 

 for it is not the direct so much as the indirect effects that 

 are so difficult to recognise and yet are so fatal: dropsy, leu- 

 cocythsemia, anaemia, debility, syncope, heart disease. A 

 school mistress sent to such a district, asked if she noticed 

 anything peculiar about the children, answered " Yes, they 

 have a bad colour, and they never never play." As Dr. 

 MacDonald says, " how could they, with scarcely enough 

 blood in them to keep them alive?" Then when people 

 are debilitated they are less able to withstand other 

 diseases, which otherwise would not kill — such deaths are 

 really due to the parasite, and yet are not set down to it 

 in the returns. This, then, is one of the diseases that call 

 for a closer study on the spot, for there is ample reason for 

 saying that were proper measures taken the disease is quite 

 preventible. And the same may be said of other diseases 

 than this one. 



The cause of malaria is an organism in the blood, an 

 animal parasite of a very lowly kind, belonging to the 

 group of Protozoa, Plasmodium malar ice, discovered by the 



