PROTOZOA 311 



since it is its property to be always breaking 

 up. 



There cannot, therefore, be any living thing of which 

 the substance, as such, is lifted above time. Yet we 

 speak of immortality, because there is a continuity of 

 life. Our own body is breaking up constantly through- 

 out life, yet we do not speak of this as death ; in fact, 

 we hardly perceive the constant process. 



In the seventh chapter we dealt with the activity of 

 the living matter, of the biogens. These have to break 

 up, it is true, but they have the power to build up one or 

 more new biogens before they die, and this secures a 

 continuity of the life. We can picture to ourselves the 

 activity of the biogens, in the growth and decay of an 

 organisation, in something like the following way. At 

 first they create several of their kind before they break 

 up, and thus effect the growth of the animal. Then 

 each produces only one biogen, and thus they maintain 

 the organism at its height. Finally, they are unable to 

 make any new biogens before they decay, and so they 

 bring about the death of the organism. 



Life can only continue to exist because there are 

 biogens the action of which is never paralysed in all 

 their generations. There are biogens that can maintain 

 life in continuity, and so bring about an immortality of 

 life. But in the multicellulars and unicellulars this can 

 only be done permanently by some of the biogens ; by 

 the others it can only be done to a certain point until 

 death. We can, however, conceive living things of the 

 simplest character, the bodies of which consist entirely 

 of such biogens. These animals might not improperly 



