ORIGIN or DISEASE AND THE GERM THEORY. 167 



his co-workers, and others, certain most valuable new lines 

 of medical treatment — all these initiations of quite modern times 

 are very intimately connected one with another, and they open 

 up quite a vista of unexplored regions. Just as the elaborate 

 science of morphology has arisen out of the crude anatomy 

 of earlier days, so must the true science of pathology be developed 

 from the basis of our present knowledge, the starting-point from 

 which we may see a dim vision of a goal. 



As a provisional explanation of the mode of development of 

 organisms, in the case of the tribe no less than in that of the 

 individual, and in many other ways, the hypothesis of evolution 

 has already been of incalculable advantage. The benefits hitherto 

 derived are, however, immeasurably enhanced by the importance 

 of the light now being thrown upon vital processes, both normal 

 and abnormal, by those who are, whether consciously or uncon- 

 sciously, now being guided by the idea of evolution in their 

 methods of research. In every department of knowledge this 

 theory is exerting the very greatest influence ; but there is no 

 science which is destined to be so profoundly affected for good 

 by it as is that of comparative pathology, the true and rational 

 science of disease. 



In fine, it must be held a primary and fundamental assumption 

 that just as all animals have presumably had a common origin, 

 in like manner all functional and structural disorders present 

 connections of the very highest interest and importance one with 

 another. In short, the. phenomena of disease are to be studied 

 from their comparative aspect, no less than by their special 

 manifestations. This is a point of view which men of light and 

 leading are now applying with the best results, and herein is 

 opened out a new field for investigation, which in the very 

 highest degree demands cultivation on account of the wondrous 

 usefulness of the knowledge which is to be gained thereby. 



And let us never falter or waver on our way upwards towards 

 the great truths above us, and never rest contented unless we are 

 climbing — it may be very toilsomely — over rocks and crags, and 

 huge mountain boulders, and beside deep chasms and pitfalls, 

 yet still always climbing upwards and onwards, higher and ever 

 higher, higher and yet higher still. 



