April 20, 1888.] 



SCIENTIFIC NE\A/S. 



565 



M. PASTEUR AND THE RABBIT 

 PLAGUE. 



The Australian rabbit plague is a novel and a most in- 

 structive experience. For the first time in history we 

 see a semi-domestic animal placed under novel circum- 

 stances, and developing into a pest, which has hitherto 

 set all human efforts and all human ingenuity at defiance. 



Fig. I. — Microbe of Chicken Cholera. 



We know that swarms of locusts have from time to time 

 occasioned scarcity, or even famine. But after a time 

 they disappear and vegetation recovers. But we cannot 

 imagine any natural process by which the rabbit plague 

 can be arrested. This will be the more intelligible if we 

 remember that this scourge has been brought on simply 



Fig. 



-Blood Globules of a Pigeon 

 Chicken Cholera. 



ATTACKED BY 



by human folly. There are in England a number of men 

 whose cherished pursuit seems to be the destruction of 

 animal life — not for food, not to prevent any danger, but 

 from the pure love of killing. Such men exist in all our 

 colonies, and especially in Australia and New Zealand. 

 As these countries did not produce animals sufficient to 



minister to the love of sport, rabbits were imported, with- 

 out a thought as to the possible consequences. Unfor- 

 tunately, the soil and the climate suited them so well 

 that, instead of producing, as in Europe, from four to six 

 litters yearly, each of three or four young ones, the 

 number of litters in Australia has reached ten, and the 

 number of young eight to ten in each. Their size and 



Fig. 3. — Microbe of Tuberculosis of Liver in its 

 Different Stages of Development from a to g. 



their voracity seem to undergo a corresponding increase. 

 The gardens are devastated ; lands, which yielded rich 

 crops of wheat or barley, have been abandoned ; the 

 vineyards and the orchards have been ruined. They eat 

 the grass down to the roots, and convert immense sheep- 

 walks, which formerly supported ten to twelve sheep per 

 acre, into bare, dusty deserts. None of the means em- 

 ployed against these enemies have led to any appreciable 

 result. They have been hunted with dogs and ferrets ; 

 they have been shot and poisoned — but they still swarm. 

 One extensive proprietor is said to have spent ^^40,000 

 in vain attempts to extirpate the rabbits, and has given up 

 the struggle in disgust. 



It has been proposed to introduce carnivorous animals, 

 such as pole-cats, weasels, and the like. But these creatures 

 multiply far too slowly to cope with such a giant evil, and 

 were they to become numerous enough they might prove 

 very undesirable. Poisons of various kinds have been 

 tried, and with temporary and local success. But if all 

 the rabbits in one plot of ground are thus extirpated, 

 those in adjacent grounds remain, and the gap in their 

 ranks is soon filled up. 



The question, therefore, is, Shall a continent like 

 Australia be lost to its inhabitants, to the British Empire, 

 and to the human race, and given over to these vermin ? 

 We think that among rational people there can be but one 

 answer : We cannot afford it ! Having tried all other 

 conceivable kinds of means, there remains but one : the 

 use of a poison which is capable of multiplying like the 

 enemy — in other words, of launching among them an 

 epidemic disease. 



A manner of doing this has been proposed by M. 

 Pasteur. He selects a disease known as " chicken 

 cholera," exceedingly infectious among poultry, rabbits, 

 and hares, but incapable of attacking human beings, 

 cattle, sheep, horses and swine, as it has been proved by 



