VI 



ANIMAL EXPERIMENTATION AND PHYSIOLOGY 



Primitive The old conceptions of physiology were born 



physiology, amid the superstitions of primitive folks. 



They had seen the organs of dead animals and 

 people, but no serious investigations of their 

 functions had been undertaken. At the height 

 of the ancient European civilization the heart 

 was regarded as the seat of the emotions, the 

 liver was the organ that regulated the passions, 

 the spleen was supposed to carry off the im- 

 purities of the body. It was believed that the 

 heart was the acropolis of the body where the 

 blood was prepared and from which it streamed 

 out through the vessels to the various parts 

 never to return. But the experimental study 

 of living animals has eliminated the errors 

 from the ancient speculations, confirmed the 

 truths, and then added to scientific knowledge 

 that great store of information which consti- 

 tutes the modern science of physiology. Every 



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