NUTRITIVE IRRITABILITY. 333 



muscles mechanically, chemically and electrically. Just 

 the same is the case with many other, small vessels, 

 which by no means exhibit nerve-fibres in all their parts. 

 In them too we can at every single point where muscles 

 exist, at once provoke contraction. 



The solution of this question has recently, as is well 

 known, been particularly promoted by the fact that, by 

 the employment of certain poisons, especially the woo- 

 rara poison, observers have succeeded in paralyzing the 

 nerves right down to their extreme terminations, or at 

 least as far as these were accessible to the experiment ; 

 and this in such a manner, that the objection cannot 

 well be raised, that the excitability of the extreme ter- 

 minations of the nerves contained in the muscle is pre- 

 served. The paralysis produced by the woorara poison 

 is completely confined to the nerves, whilst the muscles 

 just as completely retain their irritability. Whilst the 

 most violent electrical currents were made to act upon 

 the nerve in vain, without the production of the least 

 movement, the slightest mechanical, chemical or electri- 

 cal stimuli are sufficient to throw the muscle experi- 

 mented upon into a state of excitation. 



I have mentioned these facts to you, in order that I 

 might not be thought to treat the different divisions of 

 my subject too unequally. The question of function, 

 however, interests us less here. Nevertheless, you will 

 be able to gather from what I have communicated to you, 

 that now-a-days it can no longer be said with any show 

 of reason that the nerves alone are irritable parts, but 

 that we are irresistibly led to consider functional irritabi-. 

 lity, at least, as a property belonging to whole series of 

 organs. 



Far less known, gentlemen, is that clearly demonstra- 

 ble series of processes in which nutritive irritability mani- 

 fests itself that power possessed by individual parts of 



