THE BEGINNINGS OF LIFE. 53 



duce equal effects; for to say otherwise is, by impli- 

 cation., to say that some force can present more or less 

 than its equivalent effect, which is to deny the per- 

 sistence of force. Hence those parts of an organism 

 which are by its habits of life exposed to like amounts 

 and like combinations of actions and reactions, must 

 develope alike ; while unlikeness of development must 

 as unavoidably follow unlikeness among these agencies. 

 And, this being so, all the specialities of symmetry, 

 and unsymmctry, and asymmetry which we have 

 traced, are necessary consequences.' 



It is impossible to ignore the general direction and 

 bearing which the results of all the researches hitherto 

 referred to must have upon our modern conception of 

 c Life/ We have seen that in the minds of all scientific 

 men, the doctrine of the Persistence of Force, or of the 

 Conservation of Energy, as it is also termed, now rests 

 upon just as sure a basis as the really equivalent doc- 

 trine of the persistence or Indestructibility of Matter 1 . 

 And if matter and force are absolutely inseparable, if 

 the ons cannot exist without the other, it will be seen 

 that, even independently of the experimental support 

 which the doctrine has received, the reality of the 

 Persistence of Force must have followed as a logical 



1 As we have previously intimated, the popular doctrine concerning 

 the Indestructibility of Matter resolves itself philosophically into the 

 really fundamental notion of the Persistence of Force. Force and 

 Matter are two aspects of a something one and indivisible ; only the idea 

 of Matter is a conception mentally superadded to the various Force- 

 attributes which are alone correlatable with consciousness. 



