AND ITS RELATION TO ANIMAL LIFE 67 



Edinburgh, Demonstrator of Bacteriology in 

 King's College, London, says, on pages 269, 

 270 



" Whatever may be said hereinafter with 

 regard to the power of micro-organisms to cause 

 disease, we must understand one cardinal 

 point, namely, that bacteria are never more 

 than causes, ' for the nature of the disease de- 

 pends upon the behaviour of the organs or 

 tissues with which the bacteria or their pro- 

 ducts meet. VIRCHOW.' 



" The normal living tissues have an inimical 

 effect upon bacteria. It has been definitely 

 shown that the blood fluids of the body have 

 in their fresh state the germicidal power (alex- 

 ines) which prevent bacteria from flourishing 

 in them. Such action does undoubtedly de- 

 pend in measure upon the number of germs as 

 well as their quality, for the killing power of 

 blood must be limited. . . . Buchan has pointed 

 out that the antagonistic action of these fluids 

 depends in part possibly upon phagocylosis, 

 but largely upon a chemical condition of the 

 serum. . . . The blood, then, is no friend to in- 

 truding bacteria. . , .All the foregoing points 



