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ESSENTIALS OF ZOOLOGY 



who lived from 1825 to 1895. That was his way of saying that 

 scientific knowledge is simply an extension and organization of the 

 knowledge based upon common observation and experiment con- 

 cerning the facts of nature. Facts are indispensable building stones 

 of science. Facts must be gleaned from careful observations and 

 experiments which have been rigidly checked and will yield iden- 

 tical results with frequent repetition and by numerous observers. 



Fig:. 1. — Divisions of study in the field of biology. 



Science lays its foundation on accurate observations and depends 

 on the ability of the senses to reveal the truth. Established facts 

 represent truth, and the scientist respects truth while to him tradi- 

 tion or mere opinion counts for little as such. Science is, therefore, 

 a changing, increasing body of knowledge which is ever becoming 

 more thoroughly established. 



