1885.] '' Pathology, ^^ from an ^^ Evolution Point of View^ 43 



has its own character) ; the varieties as to the extent, nature, and 

 effect of the secondary affections which arise in their course ; the 

 varieties of the mode of subsidence and behaviour under treatment ; 

 their degree of mortality and contagiousness, — all these things con- 

 stitute the difficulties which surround us in our investigations as to 

 zymotic diseases. They bear on the supposed specific or constant 

 origin of disease, on the error of drawing hard and fast lines between 

 essential affections, and are with difficuUy reconcileable with the Germ 

 Theory." ^^ ^' ^^ ^' ^* ^' Reconcileable with difficulty indeed, 

 /would add, if we regard with Professor Stokes our disease germs as 

 independent and fixed entities. Reconcileable with the greatest ease 

 if we once allow our doiibts and perplexities to be illuminated by the 

 light of '' Evolution," in as far as it exercises a modifying influance 

 on our disease germs. Illuminated by this light Professor Stokes' 

 difficulties disappear not only, but so perfect a resolution of all per- 

 plexity is suggested that one is irresistibly compelled to fly to it in 

 order soundly, practically, and philosophically to clear up doubt, and 

 as irresistibly compelled to accept its ai3plication in association with 

 the Germ Theory, as one of the grand facts of Pathology. It would 

 be utterly impossible to quote here all the evidence at hand which 

 seems to me to bear upon my subject matter. 



I have been content with quoting more or less tj^pical illustrations, 

 and I hope that I have supplied in this connection additions which 

 will not be regarded as unimportant. ^* * ^' 



It remains for me only to add a word regarding the second portion 

 of my subject. That portion which deals with the internal mechanism 

 of the body, and with its adaptation to outward circumstances. 



What I said in my last paper will be remembered, and need not be 

 repeated. 



In the Lancet of December 16th, 1882, appeared a remarkable 

 lecture by Sir James Paget '' on some New and Pare Diseases," in 

 which a passage occurs so admirably emphasising what I would like 

 to express that I shall quote it verbatim. 



This is the passage: — "Perhaps the brilliant success which has 

 been achieved by the recent studies of disease-producing organisms 

 or other materials acting on us from without— a success not equalled 

 in any other field of medical enquiry — has made some think too little 

 of those changes within ourselves which occur in such ordinary con- 

 ditions of life that they may be called spontaneous. 



* ' Yet these are not less important in the production of diseases, 

 and these must be studied — just as in agriculture ^ot/^must be studied 

 as well as seeds. This is true even in respect of those diseases whose 

 essential causes are most evidently external, even of those which are 

 due to specfic contagion, their germs or seeds, if I may so speak, will 

 not germinate in an unfit soil. I suppose there is not a day in which 

 most of us do not inhale or come into contact with the germs of some 

 frequent or contagious disease ; but they do not germinate in us any 

 more than do the seeds of tropical flowers in our streets, or in the 

 fields to which the wind scatters them ; we do not offer the fitting 

 soil. And even among those in whom they do germinate the product 

 varies according to the soil. And the study cf this soil, this living soil, 

 is yet more necessary in respect of diseases which come in part or 

 wholly by inheritance ; for it is in each as personal and distinct as any 



