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Chapter 5 



How Living Things Come to be What They Are 



" Hour by hour we ripe and ripe; 

 Then hour by hour we rot and rot. 

 And thereby hangs a tale." 



THE doctrine of special creation dominated men's 

 minds for centuries. With this idea has gone the idea 

 of distinct species as facts of nature, which assumes 

 the existence of each kind of plant or each kind of animal in 

 complete separation from all others. With this background 

 for our common thought and speech, we find it difficult to 

 think of a species changing in the course of time into another 

 species, or of the descendants of one species coming to be 

 in time something different. It seems too much like asking 

 us to think that the cow may be converted into a hippo- 

 potamus or that the eggs of a snake may hatch out into 

 chicks. Nevertheless, we do accept as a matter of course 

 the marvel of an individual coming day by day to be a very 

 different kind of being. We are sure of the identity of a 

 person whom we have known for years: but no description 

 of what he was then and of what he is now would assure a 

 stranger that the latter is indeed a continuation of the former. 

 Seeing a child after a lapse of years, we are for the moment 

 impressed. How she has changed! Or is it truly the same 

 person? One need not go into metaphysical speculation to 

 solve this mystery of identity. We all accept as a fact the 

 change of an infant into a child, of a child into an adult. 



Vrefonnation 



When we raise the question of how the individual comes 

 to be what we find him to be, we are confronted with serious 



