310 NATURE AND LIFE. 



physiologist styled the vital knot, and in which he professed 

 to lodge the principle of life itself ? The point which Flou- 

 rens regarded as this vital knot is situated nearly at the 

 middle of the prolonged spinal cord that is, the middle 

 of that portion of the nerve-substance which connects the 

 brain with the spinal marrow. This region, in fact, has a 

 fine and dangerous excitability. A prick, or the penetra- 

 tion of a needle into it, is enough to cause the instant death 

 of any animal whatever. It is the very means used in 

 physiological laboratories to destroy life swiftly and surely 

 in dogs. That susceptibility is explained in the most nat- 

 ural way. This spot is the starting-point of the nerves 

 that go to the lungs ; the moment that the slightest injury 

 is produced in it, there follows a check on the movements 

 of respiration, and ensuing death. This vital knot of Flou- 

 rens enjoys no sort of special prerogative. Life is not 

 more concentrated nor more essential in it than elsewhere ; 

 it simply coincides with the initial point of the nerves ani- 

 mating one of the organs indispensable to vitality, the or- 

 gan of sanguification ; and in living organisms any altera- 

 tion of the nerves controlling a function brings a serious 

 risk as to its complete performance. There is, therefore, 

 no such thing as a vital knot, a central fire of life, in ani- 

 mals. They are collections of an infinity of infinitely small 

 living creatures, and each one of these microscopic living 

 points is its own life-centre for itself. Each on its own 

 account grows, produces heat, and displays those charac- 

 teristic activities which depend upon its structure. Each 

 one, by virtue of a preestablished harmony, meets all the 

 rest in the ways that they require ; but, just as each lives 

 on its own account, so on its account each dies. And the 

 proof that this is so is found in the fact that certain parts 

 taken from a dead body can be transferred to a living one 

 without suffering any interruption in their physiological 

 activity, and in the fact that many organs which seem dead 



