276 EXPERIMENT STATION RECORD. [Vol.38 



Tlie correlation between body pigmentation and egg production in the do- 

 mestic fowl, J. A. Harris, A. F. Blakeslee, and D. E. Warner {Genetics, 2 

 (1917), No. 1, pp. 36-77, fiffs. 16).— The authors, in consultation with W. F. 

 Kirkpatrick, have made a minute analysis by means of biometric formulas of 

 data noted (E. S. R., 33, p. 172) on the relationship between body pigmenta- 

 tion and egg production. 



The pigment measurements were restricted to the percentage of yellow oc- 

 curring in the ear lobe of White Leghorns as determined by the color top. The 

 White Leghorns studied were 309 birds entered in the 1913-14 and 375 birds 

 In the 1914-15 International Egg-laying Contest held at Storrs. Conn. The egg 

 records cover a period of one year, November to October, inclusive, of the pullet 

 year. Pigmentation determinations were made in October. 



Series of constants for mean fecundity and for variation and correlation in 

 fecundity in the White Leghorn are given. The coefficient of correlation be- 

 tween October ear-lobe color and the egg production of the year was found to 

 be —0.55. The results for the two years were in close agi-eement. On the aver- 

 age birds differing by 5 per cent in the amount of yellow in the ear lobe differed 

 by about 7 eggs in their annual production. For example, birds showing only 

 from 10 to 20 per cent of yellow in their ear lobes in October had laid on an 

 average about 185 eggs, whereas birds having from 55 to 65 per cent of yellow 

 had laid an average of about 130 eggs during the year. 



The correlation coefficients between October pigmentation and the egg pro- 

 duction of each month of the year were negative, and almost without exception 

 these coefficients were significant in comparison with their probable errors. 

 Beginning with a correlation of about — 0.15 in November, the intensity of the 

 relationship increased numerically to about — 0.25 in December, after which it 

 fell to practically zero in March and April, and then increased in (negative) 

 intensity rapidly to about — 0.75 in October. 



The hypothesis that the growth of the egg abstracts certain substances (in 

 the present case, yellow pigment) from the body tissue, or precludes its being 

 deposited there, would at once account for the generally higher correlation be- 

 tween measures made at more closely associated periods of time. If this view 

 be the correct one, egg production must be regarded as the (relatively) inde- 

 pendent variable, and intensity of pigmentation as the dependent variable. Egg 

 production would then be looked upon as the chief proximate cause of the ob- 

 served intensity of pigmentation. 



One phase of the distribution of egg production in single comb White 

 Leghorns, L. E. Card {Jour. Amer. Assoc. Instr. and Invest. Poultry Hush., 

 3 {1917), No. 5, pp. 39, 40).— The trap nest records of 106 White Leghorn hens 

 at the Connecticut Storrs Station are discussed in their bearing upon the value 

 of first year egg records as a basis for selection for high egg production (E. S. 

 R., 32, p. 73). During the first year (November 1 to October 31) these hens 

 averaged 147 eggs each, the highest record being 255 and the lowest 69 eggs. 

 For the second year the average egg production was 83 per bird, the highest 

 being 162 and the lowest 1 egg. The high producers during the first year con- 

 tinued to be the high producers during the second year. 



Chicken rearing at Morden Hall, 1914-15 {Jour. Bd. Agr. [London'^, 23 

 {1916), No. 6, pp. 563-576). — Some practical demonstrations in rearing chickens 

 by simple and inexpensive methods are reported. The trials covered several 

 years' experience in the production of about 3,000 chickens each season. 



During three years the eggs were bought from different sources and the 

 average of hatching in incubators was only 41 per cent. The following year 

 the eggs were produced at home but with no lessening of the percentage lost 

 in incubation. This was contrary to general experience and attributed to dis- 



