78 THEORY OF EVOLUTION 



In the reci^jrocal cross (fig. 40) black cock 

 by barred hen, the daughters are black and the 

 sons l)arre(l — criss-cross inheritance. These 



]"'ic.. 3fl. Sex-liiikfd iiiberilancc in - domesticated liirds shown 

 here in a cross liet\\een Itai'red Plyinoutli Koclv male and l)bick 

 Langshan female. 



inbred give black liens and black cocks, barred 

 liens and barred cocks. 



There is a case comparable to this found in 

 a wild species of moth, Abraxas grossulariata. 

 A wild variation of this t_vpe is lighter in color 



