A THEORY ',,rr.M,Y 



DEVELOPMENT AND HEREDITY 



BY 

 HENRY B. ORR, Ph.D. 



■Peofessoh at the Tulane University of Louisiana 



" Biology must put forward a conception of life applicable 

 to all its stages, from the organic process of nutrition in its 

 simplest forms to the most ideal process of feeling or 

 thought." — Harald HOffding, Outlines of Psychology, 

 p. 25. 



Wefa gotfe 

 MACMILLAN AND CO. 



AND LONDON 

 1893 



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® 



