148 Maine Agricultural Experiment Station. 1918. 



All 4 heifers are from one parent of a high producing 

 strain at the expense of quality and the other parent a low pro- 

 ducing strain but high in quality. The corrected maximum pro- 

 duction is the amount expected of the cows when they reach their 

 maximum production at mature form. The production of Num- 

 ber i seems abnormal due probably to her growth being poor as a 

 calf. Her second lactation approaches more nearly the normal 

 of her capacity with proper nutrition. In this lactation she pro- 

 duced an expected maximum for the ioo day period of 3246 

 pounds of milk and 3.6 for the fat percent. 



The difference between the production of these heifers and 

 that of their dams show, in general, that they produce the quantity 

 of milk expected of the high producing strains and the quality of 

 the low quality breed. Or put in another way, these facts sup- 

 port the hypothesis that in a cross of high producing lines to low 

 producing lines the offspring tend to have the high production of 

 the high lines. Further, the offspring of a parent producing 

 a milk of low fat content tends to have the low content of the 

 low parent even though the other parent may be from a high 

 fat content line. 



REFERENCES TO LITERATURE CITED IN TEXT. 



1. Pearl. R.. A Contribution toward an analysis of the Problem of 

 Inbreeding. Amer. Nat. Vol. XLVII, pp. 577-614. 



2. The tables included will not be found to check exactly. This is 

 due generally to the animals being too young to determine the particu- 

 lar point studied. 



3. Spillman. W. J. 1905. Mendel's Law in relation to Animal Breed- 

 ing. Rpt. Am. Breeder's Ass., 1 pp. 171-177. 



4. Wilson. J. The Colors of Highland Cattle. Soc. Proc. Dub. 

 Soc. Vol. XII, No. 8. 



5. Wright, S., Color Inheritance in Mammals. Jour. Her. Vol. XIII, 

 No. 11. pp. 521-527. 



6. Pearl, R., Variations in the Tongue Color of Jersey Cattle. 1913. 

 Proc. Soc. Prom. Agric. Sci. 



7. Bateson, W., Saunders, E. R., Rpt. I to the Evolution Committee, 

 London, pp. 1-160. 



8. Arkell. T. R., 1912. Some data on the Inheritance of Horns in 

 Sheep. Bull. 160, New Hampshire Station. 



9. Lloyd-Jones and Evvard. O. G. 1916. Res. Bull. No. 30. Agr. Exp. 

 Sta., Iowa Station, College of Agriculture. 



10. Pearl, R. 1915. Rpt. of Progress of Animal Husbandry In- 

 vestigations. Bull. 519. Maine Agr. Expt. Station. 



