BIOLOGY IN RELATION TO OTHER NATURAL SCIENCES. 445 



being physical or chemical, the organism itself naturally came to be 

 considered as a complex of siicb processes, and nothing more. And in 

 particular the idea of adaptation, wliicli, as I have endeavored to show, 

 is not a consequence of organism, but its essence, was in great measure 

 lost sight of. Not, 1 think, because it was any more possible than 

 before to conceive of the organism otherwise than as a working together 

 of parts for the good of the whole, but rather that, if I may so express 

 it, the minds of men were so occupied with new tacts that they had not 

 time to elaborate theories. The old meaning of the term "adaptation" 

 as the equivalent of "design" had been abandoned, and no new mean- 

 ing had yet been given to it, and consecjuently the word " mechanism" 

 came to be emi^loyed as the equivalent of "process," as if the constant 

 concomitance or sequence of two events was in itself a sufticient reason 

 for assuming a mechanical relation between them. As in daily life so 

 also in science, the misuse of words leads to misconceptions. To assert 

 that the link between a and h is mechanical, for no better reason than 

 that b always follows «, is an error of statement, which is apt to lead 

 the incautious reader or hearer to imagine that the relation between a 

 and b is understood, Avhen in fact its nature may be wholly unknown. 

 Whether or not at the time which we are considering some physiolog- 

 ical writers showed a tendency to commit this error, I do not think that 

 it found expression in any generally accepted theory of life. It may 

 however be admitted that the rapid progress of experimental investi- 

 gation led to too confident anticipations, and that to some enthusiastic 

 minds it appeared as if we were approaching within measurable dis- 

 tance of the end of knowledge. Sucli a tendency is, I think, a natural 

 result of every signal advance. In an eloquent 'Ilarveian oration, 

 delivered last antumn by Dr. Bridges, it was indicated how, after Har- 

 vey's great discovery of the circulation, men were too apt to found upon 

 it explanations of all phenomena whether of health or disease, to such 

 an extent that the practice of medicine was even prejudicially afiected 

 by it. In respect of its scientific importance the epoch we are consid- 

 ering may well be compared with that of Harvey, and may have been 

 followed by an undue i)refereuce of the new as compared with the old, 

 but no more permanent unfavorable results have sliown themselves. 

 As regards the science of medicine, we need only remember that it was 

 during the years between 1845 and 18G0, that Virchow made those 

 researches by which he brought the processes of disease into imme- 

 diate relation with the normal processes of cell development and 

 growth, and so, by making pathology a part of physiology, secured its 

 subsequent j)rogress and its influence on practical medicine. Similarly 

 in physiology, the achievement of those years led on without any inter- 

 ruption or drawback to those of the following generation; while in 

 general biology the revolution in the mode of regarding the internal 

 processes of the animal or plant organism which resulted from these 

 achievements, prepared the way for the acceptance of the still greater 



