3o8 



NATURE STUDY AND LIFE 



by a pair each year, and that the hfe of a robin is ten 



years, we shall have : 



1st year { 2 + lo) 

 2d " (i2 + 60) 

 (72 + 360) 



1 2 rr)bins. 



72 " 



3d 



4lh 



5th 



6th 



7 th 



Sth 



9th 



loth 



50th 



1 00th 



43- 



=.592 " 



15.552 " 



93.312 " 



559.872 " 



3.359.232 " 



20,155,392 " 



120,932,352 " 



1,61 6,400,000,000,000,000,000,000,000,000,000,000,000 " 

 1,320,000,000,000,000,000,000,000,000,000,000,000,000,000,000,- 

 000,000,000,000,000,000,000,000,000,000,000 robins. 



If we do not have all 

 the robins we want (and 

 this applies to any living 

 thing) it is because we 

 do not l<now enough 

 about rearing them or 

 are not willing to act in 

 accordance with our 

 knowledge. 



In addition to this 

 infinite power of multi- 

 plication we must never 

 lose sight of another 

 law of biology, viz., that 

 every living thing pos- 

 sesses possibilities of 

 development and im- 



FiG. 119. Young Robins Two Days Old provement. No OnC haS 



