CHAPTER XIV 



MULTICELLULAR BODIES 



We have seen that heredity adds the experiences of many 

 generations of animals, and preserves their results, to the 

 germ-plasm, which continues its life through successive 

 generations of bodies, composed of many specialized cells. 

 Let us now compare with the facts lately noted, the cor- 

 responding process in embryonic life of higher evolution. 



These mortal bodies are built up of somatic cells thrown 

 off by the master cells, in the human body construction, as in 

 lower types. The germ-cell is compounded of two half cells, 

 the large, abundantly nourished, female element called the 

 ovum, and the minute bare male element, the sperm, each of 

 which has been reduced, in expiring activity by a final act of 

 self-isolation, to singleness of chromosomes. These half 

 cells each carry an exact record or specific for their heredity, 

 that is to say a condensed compound of material molecules, 

 which has been accumulated during innumerable generations 

 of ancestors; which, if it can be induced by renewed energy 

 under similar environment, will unfold or develop, and re- 

 peat the acts of cell evolution, which those ancestors per- 

 formed. That is to say it will reproduce the structure-mak- 

 ing which is registered in it, just as if every act in succession, 

 had been recorded by the placing of a sample of the proto- 

 plasm which accomplished and endured that act. 



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