JoLY — The Abundance of Life. 71 



We turn to the consideration of old age and death, endeavour- 

 ing to discover in what relation they stand to the innate progres- 

 siveness of the organism. 



The Periodicity of the Organism and the Law of Progressive 

 Activity. 



The result of the reaction between the aggressive organism and 

 the environment, animate and inanimate, will he to impose 

 different degrees of aggressiveness upon organisms. This is an 

 unavoidable outcome of a struggle where chance of locality, &c., 

 will be sure, sooner or later, to favour one party more than the 

 other, and where adaptation of the organism is possible. Thus a 

 state of equilibrium primitively obtaining between organisms 

 would be destroyed, owing to the selective action of the inanimate 

 environment. Later on the animate environment will probably 

 quite as seriously, or more seriously, affect the organism. The 

 result of these shifting conditions of equilibrium must be, that at 

 any epoch organisms will differ in aggressiveness and in activity. 



But, further, the activity of the individual will be constrained 

 to vary at different periods of its life, ultimately resulting in a 

 state of decline and death. This variation of the individual may 

 be traced to its reaction, both with the animate and inanimate 

 environment. 



In the phenomena of old age and natural death we see events 

 in the life-history at variance with the progressive activity of the 

 organism. Was this always so ? Is the organic development of 

 the individual a process which cannot go beyond a certain period 

 of life-history, and carries the seeds of its own destruction ? For 

 the higher organism of the present day the answer must be, yes ! 

 But was it so for the organism of the past ? If we refer to the 

 unicellular organism for an answer we see at once that if this 

 organism had no power of reproduction by which to surmount 

 the difficulties of overgrowth, death might have been an inherent 

 Nemesis of growth, and the continuance of the organism impos- 

 sible. The cause of death in that case would arise and work out 

 its consummation within the individual. The reproducing uni- 

 cellular organism averts this fate, and we see, in fact, that it does 

 not die. To what causes is the natural death of the higher 



