226 



The Journal of Heredity 



5. The genetic factors governinj^ the 

 appearance of "yellow berry" have not 

 been fully analyzed, but they are evi- 

 dently distinct "from those which give 

 rise to "true softness." These factors 

 are verv sensitive to environic influ- 

 ences, and changes in climatic, soil, and 

 cultural conditions so vary the intensity 

 of their action as almost to cause one 

 to overlook their lureditarv nature. 



However, in spite of the strong regres- 

 sion from extreme selections, the al- 

 most ])erfect uniformity of results from 

 a number of carefully controlled experi- 

 ments indicate that genetic factors, for 

 a greater or less sensitivity, are in- 

 herited as definitely as are other factors 

 governing (juantitative characters. The 

 number of factors involved have not 

 been detennined. 



Selection of Laying Hens 



Since it is always of i)rinie impor- 

 tance to keep only the best layers in 

 any flock of hens, many tests have been 

 devised for selecting- good l;i\ers. 

 Some of these, such as the trap-nest, 

 have been technically satisfactory, but 

 have proven too dif^cult of operation 

 for the averag;e breeder, while many 

 others have l)een found to contain a 

 minimum of substance as well as a 

 maximum of sujjerstition. 



It has been observed that paling: of 

 the \eg color is often correlated with 

 heavy laving, which is only natural. 

 since a three ])oun(l bird, may store 

 away more than her own weight ot 

 fatty and nitrogenous substances in the 

 150' eggs >lie lavs. It has been found' 

 that by measuring the amount of yel- 

 low jiigment in the body fat, the hens 

 may be graded according to their egii:: 

 records. 



The findings of the bulletin m.iy be 

 sunnnarized as follows : 



The laying activity causes loss of 

 yellow pigment in the body fat of vari- 

 ous breeds of the domestic fowl. .\ 

 cessation of laying causes a retiUMi of 

 the yellow pigment. 



The ear lobes, vent and be.ik are the 

 parts most (piickly res])onsi\e to a 

 change in laying activitv. \\hile the 

 legs are the last to respon<l. P»y taking- 



measurements of ])igmentation in (Oc- 

 tober, the average past t:gg record can 

 be estimated. 'I'he ear lobes are most 

 readily graded by means of the color 

 top. 



When thus graded, the ])er cent yel- 

 low in the ear lobes in (Jctober shows 

 a relatively close relationship with an- 

 nual Q<fJ!;ij:; jjroduction. (This relation- 

 ship, expressed mathematically in terms 

 of the correlation coefficient, is between 

 — .5 and — .6. ) This relationship is an 

 indirect one. l)eing dependent U])on the 

 correlation existing between the laying 

 aclivit\- of the i)eriod ])reccding the 

 ])igment measurements ;ind the annual 

 <^'.gg production. 



The changes in body i)igment may 

 be used to advantage in separating the 

 high from the low producers. The 

 selection for breeders can best be done 

 in October, when only the high pro- 

 ducers are la\ing. 



( )lher characters besides p.aling of 

 \ellow pigment. \i/.. : bright color and 

 full size of comb and late molting, may 

 indicate good laxing ability. The 

 "Standard of Perfection" in dem.and- 

 ing yellow l)iaks and yellow legs pen- 

 alizes production. Changes should be 

 made in the score cards in order to in- 

 sure in ])oultrv shows better :is well ;is 

 more beautiful birds. 



' Pi«mentati()ii and Otiur Criteria for tlic Selection of Layinji lions. .Mhcrt I*. 

 Blakcsifc and J. .Artlinr Harris, station for Kxperiincntal Kvohition. Cold Siirini? 

 Harbor. L. I.; I). K. Warner. Cf)nnecticut .^gricultural College: Win. I'. Kirkpatrick. 

 Storrs .'\grionltural .Station. Storrs .Xgricultnral Kxperinient Station. Storrs. Conn. 



I'.nlletin '>2. December. 1017. 



