I06 MAINE AGRICULTURAL EXPERIMENT STATION. IQIO. 



BfL . hPl = Barred Rock 5 — a barred bird carrying good lay- 

 ing qualities, but heterozygous 

 with reference to all three char- 

 acters, and with good laying 

 associated gametically (or re- 

 productively if one prefers) 

 with the barred pattern. 

 bfl . hfl =: Cornish J^ — a non-barred bird, carrying poor laying 

 qualities, and homozygous in regard to 

 all characters 

 bPl . bfl = Cornish 5 — a non-barred bird, carrying poor laying 

 qualities, and homozygovis in regard to 

 barring and egg production, heterozy- 

 gous in respect to sex. 

 We have then for the first cross of a Barred Rock J* with 

 Cornish Indian 5 the following expectation : 



BfL . BfL X bFl . bfl — BfL . bfl = barred male birds heterozy- 

 gous in respect to all char- 

 acters except sex, 

 -|- BfL . bFl = barred females which are 

 good layers. This is, as a 

 matter of fact, what we get 

 experimentally. 

 For the reciprocal cross we have : 



bfl. bflx BfL . bFl = bfl . BfL = male birds precisely like those. 



from the other cross. This is 

 what is obtained experiment- 

 ally, at least so far as external 

 characters are concerned. 

 -|- bfl . bFl = non-barred females which are 

 poor layers. This is what is 

 obtained experimentally. 



So far as the F-^ generation is concerned the above symbolic 

 development and the experimental facts are in entire accord. 

 The interesting and important point now is : will the expecta- 

 tions deduced from the continued development of the symbolic 

 theory for the F^ generation be experimentally realized? The 

 answer to this question we hope to be able to report a year 

 from this time. 



