PBOFESSOK VIECHOW AND EVOLUTION. 415 



who, however wealthy in regard to facts, can never 

 rise into the region of principles ; and they are some- 

 times intolerant of those who can. They are formed to 

 plod meritoriously on the lower levels of thought, un- 

 possessed of the pinions necessary to reach the heights. 

 They cannot realise the mental act the act of in- 

 spiration it might well he called by which a man of 

 genius, after long pondering and proving, reaches a 

 theoretic conception which unravels and illuminates the 

 tangle of centuries of observation and experiment. 

 There are minds, it may be said in passing, who 

 at the present moment stand in this relation to Mr. 

 Darwin. For my part, I should be inclined to ascribe 

 to penetration rather than to presumption the notion 

 of a contagium animatum. He who invented the 

 term ought, I think, to be held in esteem ; for he had 

 before him the quantity of fact, and the measure of 

 analogy, that would justify a man of genius in taking a 

 step so bold. ' Nevertheless/ says Professor Virchow, 4 no 

 one was able throughout a long time to discover these 

 living germs of disease. The sixteenth century did not 

 find them, nor did the seventeenth, nor the eighteenth.' 

 But it may be urged, in reply to this, that the theoretic 

 conjecture often legitimately comes first. It is the 

 forecast of genius which anticipates the fact and con- 

 stitutes a spur towards its discovery. If, instead of 

 being a spur, the theoretic guess rendered men content 

 with imperfect knowledge, it would be a thing to be 

 deprecated. But in modern investigation this is dis- 

 tinctly not the case ; Darwin's theory, for example, like 

 the undulatory theory, has been a motive power and not 

 an anodyne. ' At last,' continues Professor Virchow, ' in 

 the nineteenth century we have begun little by little really 

 to find contagia anivuita? So much the more honour, I 

 infer, is due to those who, three centuries in advance, so 



