OF LIFE 203 



without destroying the integrity of the essential ideas contained in it ; 

 lastly, it is based on the known facts and observations which have 

 reference to this wonderful natural phenomenon. 



To begin with, in this definition active life is kept distinct from that 

 life which, without ceasing to exist, is suspended and appears to be 

 maintained for a limited time without perceptible organic movements ; 

 and this, as I shall show, is in accordance with observation. 



Then it brings out the fact that no body can possess active life 

 except when the two following conditions are satisfied. 



The first is the necessity for a stimulating cause which excites 

 organic movements. 



The second is the necessity that a body in order to possess and main- 

 tain life should be so ordered in its parts as to possess the property 

 of responding to the action of the stimulating cause and of producing 

 organic movements. 



In the animals whose essential fluids are quite simple, such as the 

 polyps and infusorians, if the contained fluids of any of these animals 

 are suddenly removed by a rapid desiccation, such desiccation may 

 be carried out without any disintegration of the organs or containing 

 parts of this animal or any destruction of the order existing in them : 

 in this case life is altogether suspended in the desiccated body ; no 

 organic movement occurs in it and it appears no longer to be a 

 living body. Yet it cannot be called dead, for its organs or con- 

 taining parts have retained their integrity, and if the internal fluids 

 are restored to this body, the stimulating cause, assisted by a gentle 

 warmth, soon excites movements, activities, and reactions in its parts 

 and henceforth it returns to life. 



The rotifer of Spallanzani, which was several times reduced to a 

 state of death by rapid desiccation, and afterwards restored to life on 

 being plunged into tepid water, shows that life can be alternately 

 suspended and renewed : it is therefore only an order and state of 

 things in a body, by means of which vital movements can occur when 

 stimulated by a special cause. 



In the plant kingdom, the algae and mosses exhibit the same pheno- 

 mena as the rotifer of Spallanzani ; mosses rapidly desiccated and 

 kept in a herbarium even for a century may return to life and fresh 

 vegetation, if they are placed in moisture at a moderate temperature. 



Complete suspension of vital movements without degeneration of 

 the parts, and hence with a continued possibility of a return of these 

 movements, may also occur in man himself, though only for a very 

 short time. 



We learn from observations made on people that have been drowned, 

 that if anyone falls into the water and is pulled out again after an 



