LECTURE II 



ARTIFICIAL SELECTION AND NATURAL SELECTION 



I now propose to consider the law to which 

 Darwin and Wallace were led, the evidence upon 

 which it is founded, and the conclusions which follow 

 from it. In the method of attack I propose to follow 

 Darwin, and I would warn you against almost 

 inevitable disappointment, for it is with common- 

 place things and facts of every-day occurrence that a 

 great theory has to deal. 



Artificial Selection. 



Domestic Pigeons. — Darwin early in his inquiry 

 felt the importance of having individual animals 

 under close observation, so that all conditions in- 

 fluencing them could be determined. For this 

 purpose domestic animals were far more suitable than 

 wild ones, and pigeons were selected for special 

 study for these reasons : — ( i ) The evidence of their 

 descent from a common ancestor is clear ; (2) Their 

 historical records extend back many centuries; (3) 

 Their variations are very great, all kinds being easily 

 kept in captivity and all breeding true. 



There are probably at least 200 kinds of pigeons 



