THE STORY OF NINETEENTll-CENTUltY SCIENCE 



This discovery very naturally reopened the entire 

 subject of brain localization. It was but a short step to 

 the inference that there must be other definite centres 

 worth the seeking, and various observers set about 

 searching for them. In 1867 a clew was gained by Eck- 

 hard, who, repeating a forgotten experiment of Haller 

 and Zinn of the previous century, removed portions of 

 the brain cortex of animals, with the result of producing 

 convulsions. But the really vital departure was made 

 in 1870 by the German investigators Fritsch and Hitzig, 

 who, by stimulating definite areas of the cortex of ani- 

 mals with a galvanic current, produced contraction of 

 definite sets of muscles of the opposite side of the body. 

 These most important experiments, received at first with 

 incredulity, were repeated and extended in 1873 by Dr. 

 David Ferrier, of London, and soon afterwards by a 

 small army of independent workers everywhere, prom- 

 inent among whom were Franck and Pitres in France, 

 Munck and Goltz in Germany, and Horsley and Schafer 

 in England. The detailed results, naturally enough, 

 were not at first all in harmony. Some observers, as 

 Goltz, even denied the validity of the conclusions in toto. 

 But a consensus of opinion, based on multitudes of ex- 

 periments, soon placed the broad general facts for which 

 Fritsch and Hitzig contended beyond controversy. It 

 was found, indeed, that the cerebral centres of motor 

 activities have not quite the finality at first ascribed to 

 them by some observers, since it may often happen that 

 after the destruction of a centre, with attending loss of 

 function, there may be a gradual restoration of the lost 

 function, proving that other centres have acquired the 

 capacity to take the place of the one destroyed. There 

 are limits to this capacity for substitution, however, and 



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