46 



THEORY OF EVOLUTION 



Tlie exj^lanation of the failure to produce a 

 jjure race of Andalusians is that thej^ are hke 

 tlie pink flowers of the four o'clock, i.e., they are 

 a hyln'id iype formed by the meeting of the 

 white and the black germ cells. If the whites 

 produced by the Andalusians are l^red to the 



Kic. IB. Diagram showing history of germ cells of cross of 

 Kig. 15. The larger circles indicate the color of the birds; 

 tlieir enclosed small circles the nature of the factors in the 

 germ cells of such birds. 



blacks (both being pure strains), all the off- 

 spring will be blue (fig. 1;5) ; if these blues are 

 inbred thev will give 1 white, to 2 blues, to 1 



