THE BREATH OF LIFE 



different? The lungs of the fish are in his gills: he 

 has to filter his air from a much heavier medium. 

 The nose of the pig is fitted for rooting; shall we say, 

 then, that the soil was made friable that pigs might 

 root in it? The webbed foot is fitted to the water; 

 shall we say, then, that water is liquid in order that 

 geese and ducks may swim in it? One more atom 

 of oxygen united to the two atoms that go to make 

 the molecule of air, and we should have had ozone 

 instead of the air we now breathe. How unsuited 

 this would have made the air for life as we know it! 

 Oxidation would have consumed us rapidly. Life 

 would have met this extra atom by some new device. 



One wishes Professor Henderson had told us more 

 about how life fits itself to the environment how 

 matter, moved and moulded only by mechanical 

 and chemical forces, yet has some power of choice 

 that a machine does not have, and can and does 

 select the environment best suited to its well-being. 

 In fact, that it should have, or be capable of, any 

 condition of well-being, if it is only a complex of 

 physical and chemical forces, is a problem to wrestle 

 with. The ground we walk on is such a complex, 

 but only the living bodies it supports have condi- 

 tions of well-being. 



Professor Henderson concedes very little to the 



vitalists or the teleologists. He is a thorough 



mechanist. "Matter and energy," he says, "have 



an original property, assuredly not by chance, which 



88 



