THE WONDER OF LIFE 635 



called osteoclasts who clear the ground, and the builders 

 called osteoblasts who build up the new construction all 

 working like busy ants. We feel that this transcends 

 mechanical categories. Reference has already been made 

 to the quite extraordinary series of events that is witnessed 

 when a larval insect, such as a fly, goes through its meta- 

 morphosis the larval body breaking down into debris, the 

 new body being built up out of the ruins on a very different 

 architectural plan. The central wonder of development 

 is the general process of differentiation, the realization 

 of the inheritance, but this is enhanced by many accessory 

 facts : there is the remarkable power the embryo often 

 shows of righting itself when the building materials of its 

 edifice have been artificially disarranged ; there are interest- 

 ing ' regulation phenomena ' by which it adjusts itself after 

 disproportions have been artificially induced ; there are 

 the strangely circuitous paths, reminiscent of ancient his- 

 tory, by which it reaches its goal ; there are the widely 

 different ways of securing the same results. 



The vitalistic argument from the facts of development 

 has found its finest expression in the work of Dr. Hans 

 Driesch, who was led to the conclusions of his Science and 

 Philosophy of the Organism by a brilliant series of embryo- 

 logical experiments. His arguments based on the study 

 of morphogenesis, or the development of form and structure, 

 are too technical for our present discussion (we have given 

 a resume of them in The Hibbert Journal, January, 1912, 

 in an article from which we have borrowed freely) ; we 

 cannot do more than indicate his main thesis. 



' Life, at least morphogenesis, is not a specialized 

 arrangement of inorganic events ; biology, therefore, is 

 not applied physics and chemistry : life is something apart, 



