CHEMICAL CHARACTERS OF CELL 89 



movement was active. Not so, says M. Le 

 Dantec, as we must suppose from the opinions 

 which he expresses, the presence of the cat 

 exercises a tactic ; influence upon the mouse 

 which obliges it to move, but its movement is 

 not an 'active one bu'fas passive as that of the 

 stone. As far as the present writer can see 

 the above is a fair statement of the views now 

 under consideration. 



If this is the case, however, there is one 

 thing quite clear, namely that the tactic in- 

 fluence must work always and unerringly 



altogether apart .fiQSL any_influ^nce^jvhich^ 

 mouse may be supposed to be able to exhibit, 

 granting for a moment that it could, if the 

 passive sport of tactisms, exercise any influence 

 over itself or anything else. This at least is 

 clear, for the rigid unbending rules of chemis- Rigid 

 try and physics would make it impossible for niles ^ of 

 any departure to arise from the regular series 

 of events involved in a chemical or physical 

 process. We may grant that a mouse does 

 usually or even invariably fly from a cat when 

 it sees one. The reaction regularly occurs. But 

 we cannot be at all sure that if a cat was 

 introduced for the first time into an island in- 

 habited by mice that they would fly from it. 

 So far as the present writer is aware the experi- 

 ment has never been tried. But very similar 



