Life of Plants and Animals 199 



One ignorant of the power of the horseshoe magnet, 

 on seeing a needle moving over a sheet of paper, in 

 obedience to the magnet beneath, would be strongly 

 tempted to ascribe to the needle both life and mind. 

 Similarly, in the case of these microscopic organisms, 

 the life and the apparent mind may be due to con- 

 cealed molecular forces. 



There is probably no molecule of matter which is 

 entirely isolated from all else. Everything is sub- 

 ject to the universal law of action and reaction. Count- 

 less influences, gravity included, may be brought to 

 bear, and the orbit of every molecule of matter may 

 be prescribed and determined by the sum total of all 

 other forces external to it. Every atom may properly 

 be said to have an ego and a non-ego striving for the 

 mastery. It is possible, therefore, that obscure internal 

 or external influences are responsible for variations in 

 the amount of vibration of the molecules, while at the 

 same time there exists a tendency to re-establish a fixed 

 arc of molecular vibration as soon as these obscure 

 causes of disturbance have ceased operating. The 

 instability of protoplasm which we call irritability 

 is a most fundamental property, giving to it this 

 power of adjustment to external forces and conditions. 

 Through these repeated adjustments the cell gradu- 

 ally changes, so as ultimately to become adapted to 

 the particular conditions amid which it lives. When 

 the cell thus responds to external influences it is said 

 to react. 



The Germ-cell or Ovum. 



Not only the reproductive spores of algi and fungi, 

 but also the germ-cells of higher plants and animals, 

 like the pollen of flowering plants, are cells. They 

 have most of the characteristics enumerated above, 

 the physiological and many morphological characters 

 being identical. 



