390 THE WORLD OF LIFE chap. 



view of the marvels of " growth " and cell-division in living 

 organisms. In the Address already quoted, Prof. H. E. Arm- 

 strong says, after referring to some of the complex and 

 extraordinary chemical transformations produced by living 

 plants : 



"The general impression produced by facts such as these is, 

 that directive influences are the paramount influences at work in 

 building up living tissues." 



And again more explicitly : 



" It would seem that control is exercised and stability secured 

 in several ways ; not only is the form laid down in advance but 

 certain chosen materials are alone available, and the builders can 

 only unite particular materials in particular ways." 



It is very satisfactory to find that both chemists and 

 physiologists recognise the absolute need of some controlling 

 and directive power in elaborating the special products or 

 building up the complex tissues of plants and animals. 



The Cause and Purpose of this Variety 



The general conclusion to which the whole argument of 

 this volume tends, is, that the infinite variety we see in 

 nature can be traced back step by step to the almost infinite 

 complexity of the cells by means of which they live and 

 grow ; of the protoplasm which is the substance of the cells ; 

 of the elements of which protoplasm consists ; of the mole- 

 cules of those elements ; and finally of the atoms whose 

 combination forms the separate and totally distinct ele- 

 mentary molecules. And at each step farther back we are 

 as far off as ever from comprehending how it is possible for 

 such infinite diversity to be brought about. And now that 

 we are led to believe that the atom itself is highly complex — 

 that it is a system of revolving electrons or corpuscles, held 

 together by tremendous forces — the mystery becomes deeper 

 still, and we find it quite hopeless to realise what is the 

 nature of the controlling power and mind, which out of such 

 unimaginable entities has built up the vast material universe 

 of suns and systems of which our earth forms a fractional 

 part, together with that even more complex world of life of 

 which we ourselves are the outcome. 



! 



