18 ANIMAL INDIVIDUALITY [CH. 



not Life's power of renewing themselves, of " sprout- 

 ing fresh and sweet continually out of themselves " 

 like protoplasm, yet all the time are being exposed 

 to the inclemencies of the world and the assaults of 

 enemies: at last something, the oldest part, gives, 

 and involves the whole fabric in its fall 1 . 



Death of the substance that has been the result 

 whenever Life has allowed unlimited growth to the 

 individual : and when she preserves the substance, 

 as in the Protozoa, by dividing it into two whenever 

 it has reached a certain size, so keeping the pattern 

 of the race within a narrow range, easily controlled, 

 then there must be death of the individuality. She 

 has never been able to produce an individuality 

 which can for ever keep the unstable structure of its 

 substance nicely balanced against the chance violences 

 of the outer world. 



But and this is important when the Protozoan 

 divided its substance and destroyed its individuality, 

 two fresh ones sprang up in the two separate masses 

 of substance. The relation of the organism's in- 

 dividuality to its substance will be considered at 

 more length in Chap. VI. Here it can only be said 

 that protoplasm has primitively a great power of 

 self-regulation, so that the plan of the individual's 

 structure which is characteristic for the species can 



1 As examples will serve, the hollow trunks of aged trees, the 

 brittleness of old bones, and the decay of teeth. 



