The Process of Life. 31 



plasm, the plasmogen, enclosing within its meshes a more 

 fluid material, the plasm. It is probable that this more 

 fluid material is an explosive, elaborated through the vital 

 activity of the protoplasmic network. During the period 

 of repose which intervenes between periods of activity, the 

 protoplasmic network is busy in construction, taking from 

 the blood-discs oxygen, and from the blood-fluid carbona- 

 ceous and nitrogenous materials, and knitting these 

 together into relatively unstable explosive compounds. 

 These explosive compounds are like the mixed air and gas 

 of the gas-engine. A rested muscle may be likened to a 

 complex and well-organized battery of gas-engines. On 

 the stimulus supplied through a nerve-channel a series of 

 co-ordinated explosions takes place : the gas-engines are set 

 to work ; the muscular fibres contract ; the products of the 

 explosions (one of which is carbonic acid gas) are taken 

 up and hurried away by the blood-stream ; and the proto- 

 plasm sets to work to form a fresh supply of explosive 

 material. Long before the invention of the gas-engine, long 

 before gun-cotton or dynamite were dreamt of, long before 

 some Chinese or other inventor first mixed the ingre- 

 dients of gunpowder, organic nature had utilized the 

 principle of controlled explosions in the protoplasmic cell, i 

 Certain cells are, however, more delicately explosive 

 than others. Those, for example, on or near the external 

 surface of the body those, that is to say, which constitute 

 the end organs of the special senses contain explosive 

 material which may be fired by a touch, a sound, an 

 odour, the contact with a sapid fluid or a ray of light. 

 The effects of the explosions in these delicate cells, rein- 

 forced in certain neighbouring nerve-knots (ganglionic 

 cells), are transmitted down the nerves as along a fired 

 train of gunpowder, and thus reach that wonderful aggre- 

 gation of organized and co-ordinated explosive cells, the 

 brain. Here it is again reinforced and directed (who, at 

 present, can say how?) along fresh nerve-channels to 

 muscles, or glands, or other organized groups of explosives. 

 And in the brain, somehow associated with the explosion 



