2i 4 AGE, GROWTH, AND DEATH 



of the most impressive sights which I have ever 

 seen has been the sight of the heart of a quadruped, 

 a dog, continuing to beat after it had been taken out 

 from the body. The dog was dead the rest of the 

 body was dead but the heart lay upon the physio- 

 logist's table, beating. The experimenter could sup- 

 ply it with the necessary circulation. He could give 

 stimuli to it, and under these favourable conditions 

 make important discoveries in regard to the function- 

 ing of the heart. So, too, I myself made experiments 

 upon a muscle once part of a living dog, separated 

 entirely from the parent body, supplied with its own 

 artificial circulation, and from those experiments was 

 able to discover some new unexpected results in re- 

 gard to the nutrition of the muscle, and the changes 

 which chemically go on in it. 1 This over-living, then, 

 of the parts of the body, their separate life, is some- 

 thing which we must familiarise ourselves with, and 

 the great importance of which we must carefully ac- 

 knowledge, for much of the benefit which the medi- 

 cal practitioner is able to render to us and to our 

 friends to-day is due to the knowledge which has been 

 derived experimentally from the study of the over- 

 living or surviving parts of a body which as a whole 

 was dead. 



Death is not a universal accompaniment of life. 

 In many of the lower organisms death does not 



'Charles S. Minot, " Die Bildung der Kohlensaure innerhalb des ruhenden 

 und erregten Muskels," Ludwig's Arbeiten der Physiol. Anstalt, Leipzig, 

 xi., 1-24 (1876). 



