14 ADAPTATION AND DISEASE 



that on the whole we are more likely to obtain results where 

 this levelling action of conjugation is wanting. 



I propose, therefore, to take up first the evidence of adapta- 

 tion as affecting the pathogenic bacteria, next, of adaptation as 

 it affects man and the higher animals, and, lastly, to discuss the 

 application of the data brought forward to our conception of 

 disease and disease processes on the one hand, of the evolutionary 

 process on the other. 



