Fig. 6. Plymouth Rock hen— a bird which lacks counter-shading— against a flat background of 

 Plymouth Eoc;k hen skins, demonstrating the same thing as Fig. 7. 



Photographed from life. 



Fi'- '■ J^'''^" J?7'' }^S^™« counter-shading, against a flat white cloth. To show that a monochrome 

 object can not be 'obhterated,' no matter what its backgronnd. u^i.iuun, 



Photogi'aphed from life. 



