96 THE ZOOLOGIST. 



Thakombau left Fiji to pay a visit to the Governor of New South 

 Wales at Sydney, on the occasion of his cession of his realm to 

 the British Crown. While there he contracted measles, a disease 

 entirely unknown in Fiji ; and unfortunately returning home 

 before he was free from the microbes, these minute particles 

 spread to his immediate attendants, and grew and multiplied in 

 them, till at last the disease swept like a storm over the islands, 

 and no fewer than 40,000 people out of that small population died 

 from its effects. After four or five months the epidemic ceased in 

 its virulent character, and now measles there is scarcely more 

 severe than in Europe. 



" In the same way, I am informed that the growth of the briar- 

 rose in Tasmania, which at one time threatened such great mis- 

 chief to that colony, is now far more easily controlled than at first ; 

 and that thistles in Victoria — partly, no doubt, through the special 

 legislation, but partly also from the exhaustion of certain ingre- 

 dients in the soil — are becoming greatly restricted in area. Now 

 in France the plants, the animals, the diseases have, for thousands 

 of years, been adapting themselves to each other, and, if I might 

 use a rather far-fetched simile, they have established a modus 

 Vivendi. 



" Here we have new birds, new animals, a virgin soil, and new 

 climate conditions. Who can tell what results will occur when 

 these are brought into contact with a new choleraic disease ? 

 Next, besides the fact that in France the choleraic microbe is on 

 a worn-out soil, — worn out for its own purposes, I mean, — we 

 must remember that the frosts and snows and rains of the long 

 winter there are unfavourable to the extension of the microbe, 

 while in that country of small farms, where every range of trees, 

 every growing field, acts as a filter, the conditions are totally dis- 

 similar to those on our vast sweeps of plain, ' growing weather ' 

 all through the winter, and dust-winds raking the country straight 

 down from the Rabbit-infected fields to the fertile districts of the 

 coast. Is there, then, any certainty as to what would be the 

 result of the introduction here of this poison ? There is no cer- 

 tainty. Microbes of some of the most malignant diseases are 

 sterile in certain countries ; thus, although typhus fever is 

 endemic in England and Ireland, we have never had one case in 

 Australia — it seems as if it could not live out here ; and the 

 poison of the yellow fever of America dies out rapidly in England. 



