AS THE BIOLOGIST SEES IT 



sugar is composed, although these atoms 

 are arranged within the molecules in a 

 way slightly differing from their arrange- 

 ment in sugar, may find himself poisoned 

 instead of strengthened. Or, the man 

 who accepts the statement of the zoologi- 

 cal morphologist that the nervous system 

 of a certain animal differs primarily 

 from that of another in that there is not 

 quite so much of it, but that it is, as far as 

 it goes, of essentially the same kind, and 

 who therefore expects to find his first 

 animal exhibiting the same kind of sense, 

 only not quite so much of it, as his 

 second, will be much surprised when he 

 becomes really acquainted with the sense 

 differences of his two animals. 



Nevertheless the biologist has good 

 grounds for paying much attention to 

 commonness of origin and similarities of 

 structural make-up in his attempts to 

 read the riddle of life, even human life. 

 Things that have come from the same 

 thing, or that have a fundamental like- 

 ness of structure, are bound to have some 

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