DISEASES OF TflE OX AND SHBHP. 263 



most profound importance that, when seen, cattle-plague should 

 be at once diagnosed ; otherwise the disease may gain such 

 headway in the country that even the most severely repressive 

 measures may for a long time prove ineffectual in staying its 

 progress. 



For convenience' sake the disease may be studied under the 

 two chief forms, called respectively benignant and malignant, 

 into which it has, perhaps somewhat arbitrarily, been divided. 



Benignant Cattle-Plague. — This type of the malady is 

 seen in Eastern Europe, where it is always liable to be met 

 with. In these regions it is, so to speak, indigenous, and 

 having broken out among the ancestors of the cattle living there 

 from time to time, it seems to have lost the great powers which 

 we may suppose it exercised over the cattle subjected to its 

 influence in past times. The oxen have become accustomed to 

 the invasion of these germs into their blood and tissues, and 

 cattle have, by reason of the continued survival of those which 

 are best fitted to resist the attacks of cattle-plague, been 

 developed with the power of resisting the growth and 

 multiplication of these micrococci. Indeed, in dealing with 

 the activities of living organisms, whether animals or plants, 

 one continually meets with analogous cases in which the power 

 of adaptation is most strikingly shown. 



Opium-eaters, arsenic-eaters, tobacco-chewers, and great 

 smokers, in common with those who consume large quantities of 

 alcoholic stimulants, exemplify, in the case of mankind, how 

 largely the system can gain the power of resisting the influence 

 of disturbing factors, which in the first instance would have 

 exerted a highly pernicious influence. Those who are addicted 

 to the harmful habit of smoking in excess scarcely realise the 

 potency of the drug which seems to them to be merely a 

 soothing sedative. Yet it is well known that a few drops of the 

 fluid which has collected in the stem or bowl of a foul pipe 

 will, if placed in the mouth of a frog or toad, kill the animal ; 

 and the obvious corollary to this observation is that on no 

 account should smoking be indulged in to an inordinate degree. 

 Further, if the smoker will recall the first pipe or cigarette he 

 tried, he will recognise that the power of resisting its unpleasant 

 effects has only gradually been acquired. Thus it is, too, though 

 by no means to the same extent, in the case of diseases, and 



