BIOLOGY IN HUMAN AFFAIRS 



Edmund B. Wilson, has happily had the individual experi- 

 ence of seeing the establishment of the theory that all 

 cells come from pre-existing cells; of seeing the proper 

 description of cell division and of fertilization; the identifi- 

 cation of the cell nucleus as the most important cell organ; 

 the discovery that the chromosomes, w^ith their peculiarly 

 exact methods of division, are the material basis of hered- 

 ity; and finally, of seeing the determination of the archi- 

 tecture of the germ plasm and of the mechanism by which 

 the units of heredity, the genes, are transmitted to the 

 succeeding generation. 



Physiology, as I have said, had its birth in the researches 

 of Harvey; but for two centuries and a half it led a rather 

 moribund existence. It was restored to vigor by the genius 

 of Johannes Miiller (1801-1858), of whom Verworn said: 

 "He is one of those monumental figures that the history 

 of each science brings forth but once." Miiller was not only 

 a great investigator, he was a most stimulating teacher. 

 Du Bois-Reymond and Helmholz are two of the dis- 

 tinguished scholars whom he led into scientific work. 

 Miiller' s contributions to physiology were prodigious, yet 

 he is revered to-day less for the specific results of his re- 

 searches than for his innovations in physiological method- 

 ology. He made controlled experiments, he studied animal 

 behavior, he introduced quantitative measurements, he 

 interpreted results both in the terms of physics, chemistry, 

 and mathematics, and in the terms of psychology. In 

 fact, it was from Miiller's laboratory that there came the 

 first recognition of the close association between the 

 operations of the mind and the functioning of the central 

 nervous system. 



Physiology, in the seventy-two years since Miiller's 

 death, has probably made the greatest progress of any of 

 the biological subdivisions. The introduction of quantita- 

 tive methods permitted the statistical study of sensation, 



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