THE RELATIONS OF PATHOLOGY 107 



can fail to see much that must be useful and advantageous in the 

 complex reactions to injuries observed in inflammations, the sig- 

 nificance of which has been greatly broadened through the well- 

 known comparative study of Metchnikoff. In the case of immunity, 

 natural and acquired, our wonder knows no bounds, so marvelous 

 are the precision and scope of the protective reactions, concerning 

 which so much has been brought to light in recent years and which 

 lend themselves well to comparative studies. In the case of de- 

 generations and tumors it is not possible to recognize any direct 

 or indirect advantage, and certainly no one has yet been able to 

 see malignant tumors in such favorable light. In these instances 

 first mentioned the pathologic reactions have physiologic proto- 

 types ; they are adaptations of physiologic processes. Regeneration 

 and growth are taking place constantly in health. Phagocytosis, on 

 which so much stress has been laid in inflammation, is merely an 

 exaggeration of normal nutritive processes in certain cells. At pre- 

 sent the production of antitoxins and other anti-bodies is best ex- 

 plained as the result of special adaptations of normal stereo-chem- 

 ical mechanisms whereby nutrition is carried on. A very noticeable 

 difference between the physiologic and pathologic manifestations of 

 these functions is seen in their imperfections and shortcomings 

 under many of the abnormal conditions. Incomplete regeneration 

 resulting in the formation of scars often has many disadvantages. 

 Inflammations frequently establish conditions in themselves fraught 

 with dangers. The reactions of immunity may not neutralize 

 quickly enough the toxins nor destroy promptly enough the in- 

 vading organisms. Hence there is abundant scope for the inter- 

 vention of the physician armed with all the various appliances of 

 his art, some of the most useful of which are the products of arti- 

 ficially produced biologic reactions. But after all the individual 

 organisms must enjo)^ the best chances for survival and reproduc- 

 tion that suffer least harm because best able to adapt themselves 

 and to protect the life and function of their cells under conditions 

 of disease. 



Just as there are variations in the limits of physiologic regulatory 

 mechanisms, so also there are individual differences of degree in 

 the power of adaptive and protective reactions to establish them- 

 selves in disease and permit continuance of life. In progress- 

 ive evolution it naturally must be in the descendants of individuals 

 with the best adaptive and protective powers that an increasing 

 completeness and perfection of such powers will be found. Viewed 

 in this light many processes of disease assume a significance of 

 positive character in biologic evolution, a point of view that would 

 increase the interest in pathology among biologists in general, 

 and thus tend to further its development along broader lines and 



