INORGANIC AND LIVING BODIES 193 



which animates them and gives them activity, and because this factor 

 requires their co-operation for a common end both in the separate 

 organs and in the entire individual ; because, moreover, the variations 

 in this same factor work similar effects in the state of each molecule 

 and each part. 



5. No inorganic body needs any movement in its parts for its 

 preservation ; on the contrary, so long as the parts remain at rest 

 the body is preserved without disintegration and might exist in this 

 condition for ever. But as soon as any factor begins to act upon this 

 body and produce movements and changes in its parts, the body at 

 once loses either its shape or its coherence, if the movement and changes 

 produced in its parts merely affect its mass or some part of its mass ; 

 and it loses even its fundamental character or is destroyed, if the 

 movements and changes in question penetrate as far as its integral 

 molecules. 



Every body possessing life, on the other hand, is permanently or 

 temporarily animated by a special force, which incessantly stimulates 

 movements in its internal parts and uninterruptedly produces changes 

 of state in these parts, at the same time effecting restorations, re- 

 newals, developments and a number of phenomena that are entirely 

 peculiar to hving bodies ; so that in their case the movements stimu- 

 lated within them produce disintegration and destruction followed by 

 recuperation and renewal. This prolongs the life of the individual 

 so long as the equilibrium between these two opposed elements is not 

 too rudely disturbed. 



6. In all inorganic bodies an increase of volume and mass is always 

 accidental and has no necessary hmits. This increase only takes 

 place by juxtaposition, that is to say, by the addition of new parts to 

 the external surface of the body in question. 



The growth of every living body, on the contrary, is always necessary 

 and hmited, and only takes place by intussusception, that is to say, by 

 internal penetration, or the introduction into the individual of sub- 

 stances which have to be added to it and make part of it after being 

 assimilated. Now this growth is a true development of parts from 

 within outwards, and is exclusively the property of hving bodies. 



7. No inorganic body has to feed in order to be preserved ; for 

 it need never lose any of its parts, and when it does it has no means of 

 restoring them. 



AU living bodies, on the contrary, necessarily experience in their 

 internal parts successive and constantly renewed movements, changes 

 in the state of the parts, and, lastly, continual losses of substance 

 through the separations and dissipations involved by these changes. 

 Hence no such body can maintain Ufe if it is not constantly feeding, 



