226 Hormones 



but racial evolution as well is growing rapidly in 

 men's minds, and this opens up great possibilities. 



Perhaps we may make the fallacy of "biologisms" 

 more vivid by taking the particular case of the influ- 

 ence of the ductless glands on human development 

 and activity. This influence is indubitable and far- 

 reaching, but it may be exaggerated into a fallacy 

 which pictures man as the slave of his hormones. 



There is a strong tendency nowadays to shirk per- 

 sonal responsibility. If things are not well with us, 

 we blame our heredity. If that won't work, we blame 

 our "unconscious mind." When the worst comes to 

 the worst, we blame our "glands." When things are 

 going well with us, however, we are quite willing to 

 take the credit to ourselves. 



Apart from some earlier guesses at truth, the first 

 glimpse of the idea of internal secretions, which are 

 not got rid of on a free surface, nor carried away by 

 ducts, may be found in the work of the great French 

 physiologist, Claude Bernard, especially in his dis- 

 covery that the liver was a maker of glycogen or 

 animal starch. The second great step was due to 

 Brown-Sequard, who gave some experimental evi- 

 dence in support of his brilliant idea that glands 

 (and other organs) make definite contributions to 

 the blood, and that these have a profound influence on 

 the whole system. The third step was taken by Pro- 

 fessors Bayliss and Starling, who put the theory of 

 internal secretions on a firm basis, and proved, for 

 instance, that a specific chemical messenger, called 

 secretin, is manufactured by glands on the wall of 



