io6 PRESENT-DAY RATIONALISM 



gizzard perform the office of the mill-stones, the craw or 

 crop supplies the place of the Jiopper. 



" Nor does the gizzard belong to birds as such. A 

 gizzard is not found in birds of prey. Their food re- 

 quires not to be ground down in a mill. The comparatory 

 contrivance goes no farther than the necessity." 



In other words, it is an illustration of the Principle of 

 Least Action. 



Degeneration, so commonly occurring in organs of 

 animals and plants, was a great stumbling block as long 

 as every kind of structure was supposed to be created as 

 it now is and " very good ". 



Of course the interpretation by degeneracy under 

 Evolution is perfectly sufficient. It is one of the several 

 lines of evidence which together prove inductively that 

 man is descended from the animal world. 



