Place of Definition, etc., m Philosophical Biology 111 



that object, as any attribute whatever can furnish. 



Suppose the mother of our hypothetical island child 

 had a mole on her chin; or that the sunshine brought 

 out freckles on her nose which disappeared again dur- 

 ing the winter. These marks would be accidents, ac- 

 cording to logic; and biologically regarded would be 

 quite insignificant. But they would be as indubitable 

 elements in the child's knowledge of its mother as any 

 other elements that can be mentioned. 



Let me ask any reader who is "keen" enough on the 

 different kinds of automobiles to be able to distinguish 

 most of the "makes" as they are passed on the road, 

 what marks he relies on for identifying each type of 

 car? Is it not true that in most cases you depend upon 

 one or a few very trivial things ? Color comes in ; but, 

 on the whole, one finds himself giving less attention for 

 identification purposes to this conspicuous attribute 

 than to others far less conspicuous. Just now the 

 shape and color, not the name, of the manufacturer's 

 plate placed on the radiator of so many machines, is a 

 good identification mark for machines coming toward 

 one. For the rear view of a machine with the top up, 

 the number and shape of the window panes in the back 

 curtain are useful marks. 



The purely logical points deserving emphasis in this 

 familiar but typical case are : first, the trustworthiness 

 of the identification marks in spite of their triviality. 

 The number and shape of the windows in the back cur- 

 tain are just as positive and real as traits, that is, 



