In the early days of the settlement of Australia, enterprising settlers unwisely introduced the European rabbit. This rabbit had no natural enemies in the antipodes, so that it multiplied with that promiscuous abandon characteristic of rabbits. It overran a whole continent. It caused devastation by burrowing, and by devouring the herbage, which might have maintained millions of sheep and cattle. Scientists discovered that this particular variety of rabbit, and apparently no other animal most susceptible to a fatal virus disease, myxomatosis. By infecting animals and letting them loose in the burrows, local epidemics of this disease could be created. Later, it was found that there was a type of mosquito which acted as the carrier of this disease and pass it on to the rabbits. So while the rest of the world was trying to get rid of mosquitoes. Australia was encouraging this one. It effectively spread the disease all over the continent and drastically reduced the rabbit population. It later became apparent that rabbits were developing a degree of resistance to this disease, so that the rabbit population was unlikely to be completely exterminated. There were hopes, however, that the problem of the rabbit would become …