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THE AMERICAN NATURALIST [Vol. LV 



indicating ovarian activity and tlie onset of laying, ap- 

 pear to pass tlirough a molt or partial molt whereby the 

 dark feathers of the back region particularly, are gradu- 

 ally rfi)l;H't'(l hy those of a clearer blue. The necks of 

 such tViualo LiMially remain dark, showing considerable 

 contrast with Xhv other regions of the body, though being 

 by no means as dark as the same region of the blue male. 



Although the number of desexed males into which 

 ovaries were introduced was small, it seems fair to con- 

 clude in the light of the evidence concerning testicular 

 (Goodale, IS)l(i) and ovarian (Goodale, 1918; Cole and 

 Lippincott, imi*) iiiHiK iu-c in fowls that the failure of the 

 factor R to ex})i-ess itsi'lf as fully in the neck, back and 

 saddle regions of the l)lue and blue-splashed males as in 

 the females is due to the lack of some necessary co- 

 operative action on the part of the ovary, and not to any 

 inhibitive action on the part of the testis. 



y. The Beeedixg Behavior of Andalusians 

 New data concernitig the breeding behavior of the three 

 coloi- t\ pes ot Andalusians. as shown bv scvci-al types of 

 matin-, aiv pi-.-^cntrd in Table 1. 



(lie) (rE) (Re) (Re) 



