INTRODUCTION 



Living and Non-Living Matter 



Each plant and animal has a definite size 

 limit and form characteristic of the 

 species. 



Living organisms grow by intussusception, 

 the addition of particles of protoplasm 

 prepared from their food by metabolic 

 processes. 



Living organisms contain certain ele- 

 ments characteristic of protoplasm, and 

 Including complex proteins, built up from 

 Carbon, Hydrogen, Oxygen and Nitro- 

 gen, and undergo constant tearing down 

 (katabolism) and upbuilding (anabo- 

 llsm). 



Living organisms are able to reproduce 

 complete Individuals like themselves, and 

 to regenerate mutilated portions. 

 Besides growth and reproduction, living 

 matter has other powers: contractility, 

 irritability, nutrition, respiration and ex- 

 cretion. 



There is no limit to the size ^ or form 



reached by non-living matter (e.g. 



water). 



Non-living bodies grow by adding to 



themselves on the outside by accretion,^ 



accumulations of material chemically the 



same. 



Non-living matter may contain the same 



elements but be lacking In the spark of 



LIFE. 



Non-living matter Is utterly unable to 

 reproduce. 



Non-living matter is devoid of these 

 characteristics. 



Protoplasm 



Protoplasm is the term used to indicate that complex substance 

 from which all living things are built up. Protoplasm is somewhat 

 jelly-like in appearance, and nearly colorless, but may be opaque 

 when it contains food particles. It is considered to be an emulsoid, 

 existing either as an apparently liquid sol, with minute invisible 

 molecules; or as a gel, firm in consistence, with larger visible par- 

 ticles. Protoplasm is made up of "unit masses," which we term 

 cells. Each cell has a nucleus and cytoplasm. Plant cells may 

 have a cellulose wall, but in animal cells a cell wall is frequently 

 absent. 



Structure of the Cell. — A cell is a complex living system or 

 physiological unit of protoplasm which contains a nucleus. The 

 protoplasm outside of the nucleus is usually called "cytoplasm." 

 All the contents of the cell have been shown to be the seat of vital 

 activity, but the nucleus contains certain elements, colored readily 

 by dyes, hence called chromatin granules, which a vast amount of 



^ Since radiation pressure will in the end overcome gravity, even the mass of a star 

 beginning as a nebula cannot exceed a certain limit. Nature abhors infinity of size. 

 (J. A. Elesland.) 



^ Huxley cited crystals as an example of accretion. We now believe that crystals 

 are assembled by electrical forces less complicated than in organic combinations. 



