70 THE SUM IMPRESSION 



fighting in the air— and so a new organ is pro- 

 duced : an essentially purposive structure such as the 

 eye or the lung, though unpurposed before the need 

 arose. The organs we see, therefore, are outward 

 and visible signs of the existence within of a definite 

 striving towards an end — that is, of a purpose. 



The forest shows an abundant, varied, and 

 intense life in which individuals are for ever battling 

 with one another. But all is not happening by 

 chance. Everywhere we see signs of purposive- 

 ness. Purposiveness — the striving towards an end — 

 stands out as a dominating feature in forest life. 

 Selections and adaptations are made, but they are 

 made with some purpose in view. Purpose governs 

 the adaptations and selections. What that purpose 

 is we shall try and discover as we get to know still 

 more of Nature. 



So far we have been observing individuals as 

 separate individuals. Now we must look at them 

 gathered together as a whole. And the first point 

 we note is that though each individual has his own 

 unique individuality, whether he be plant or man, 

 all are kept together as a single whole. We have 

 seen the individuals battling with one another, com- 

 peting with one another, struggling against one 

 another. But that is only one side of the picture. 

 Just as remarkable as the way in which they have 

 to resist one another is the way in which they 

 depend on one another. Their interdependence is, 

 therefore, the point we have now to note. 



Since Darwin drew our attention to the struggle 

 for existence and survival of the fittest, the per- 



