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THE AMERICAN NATURALIST [Vol. LV 



stantiation. It seemed desirable from several standpoints 

 to ascertain what factors were involved in the production 

 of Orpington blue, and whether the blue Orpington dif- 

 fered from the blue Andalusian in its genetic behavior. 

 A number of matings were accordingly made, the data 

 from which are shown in Table VI. 



These data are consistent with the supposition that the 

 factors involved in the production of Orpington blue are 

 identical with those which produce Andalusian blue. The 

 crossing of blue Andalusians and blue Orpingtons gave 

 exactly the same sort of result as that obtained by mating 

 blue Andalusians inter se, as shown by group 1. The 

 blue-splashed Orpingtons mated with white Wyandottes 

 gave only blues (group 4) just as did the blue-splashed 

 Andalusians. And finally the ratio from white 

 Wyandotte X blue-splashed Orpington crosses gave the 

 same phenotypic classes as were obtained in the from 

 the white Wyandotte X blue-splashed Andalusian cross, 

 with a deviation from expectancy as great as would be 

 ])rol)able once in four times. It is interesting to note that 

 wliilc the white class is deficient in this case, the blue- 

 -l)l.-i>lir(l chiss is not. 



XII. Data from Blue Leghorn Crosses 

 In the spring of 1917 there appeared in the large pure- 

 bred single comb white Leghorn flock of the Pabst Stock 

 Farm at Oconomowoc, Wisconsin, two l)hie females. The 

 flock was not pedigreed and nothing known of the indi- 

 vidual ancestors of these birds. Tlu \' wwr of fair Leg- 

 horn type and were, as far as known, the offspring of 

 pure-bred white Leghorn parents. Through the courtesy 

 of Mr. Fred Pabst, and Dr. L. J. Cole of the University 

 of Wisconsin, these individuals came into the hands of 

 the writer and were entered on the records of the Dcpart- 

 nirut of Ponltry 1 1 nsl.nn.lry <.f lh.' Kansas Stale Agricul- 



