CHAPTER XI 



ORGANIZATION, VITALITY, AND MORTALITY 



Life, a Complicated Phenomenon 



A YOUNG organism, recently emerged from a cyst, or just 

 after conjugation, is in perfect condition to respond to 

 the stimuli of its normal environment. The initial changes of 

 the fundamental organization brought about through absorp- 

 tion of water and by oxidation, have already resulted in the for- 

 mation of the characteristic structures of the derived or adult 

 organization. As soon as these are formed the normal life of 

 the organism begins. Through constant oxidations and other 

 chemical processes, whereby energy for the varied movements 

 and activities of the organism is provided, various substances are 

 broken down and different substances are formed. Through 

 movement food substances are taken in; these are hydrolyzed 

 and distributed throughout the protoplasm in the form of nitro- 

 gen-holding proteoses,* amino acids, and simple carbohydrates 

 like grape sugar. Some of these are utilized in the up-building 

 and growth of the protoplasmic constituents, but much is stored 

 up as granules of albumen and starch-like products, which, to- 

 gether with lipoid (fat-like) substances, become the energy- 

 holding reserves which are the first to disappear under conditions 

 of starvation. 



By reason of these continued activities of waste, repair, and 

 growth the protoplasm is constantly changing in composition 

 until an optimum is reached, at which time new activities are 

 set up. 



Periodic Reorganization 



These are the activities of division, which are fairly well 

 known morphologically, but about the causes of which we are 



* Proteoses, any of a class of intermediate soluble products formed from 

 proteids by digestion with gastric and pancreatic juices, or by the hydrolytic action 

 of acids and alkalies. 



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