Studies in Milk Secretion 143 



transmitting qualities of his son's (Queen's Raleigh) daughters 

 in their milk production, lowered their butter- fat percentage 

 and made a net gain in their butter-fat of 38.32 pounds on the 

 average for each daughter. Among the other bulls of table 9 

 whose sons raised their daughters is Fontaine's Duke. 



Of those which lowered the transmitting qualities of their 

 sons for butter-fat Mabel's Poet, Island Lodestar and Hood 

 Farm Golden Fern's Lad stand in about the order named as 

 to their worth in transmitting high milk and butter-fat pro- 

 duction to their sons. 



Ancestral Analysis of Sires .with Superior and Inferior 

 Transmitting Powers for Milk Production, Butter- 

 Fat Percentage and Butter-Fat. 



On page 102 the authors defined their conception of what 

 constitutes a superior bull. Table 8 contains the list of such 

 superior sires arranged according to their merit. Following 

 this discussion is given a list of the inferior sires as judged by 

 what their progeny did. These two lists contain the sires at 

 the two extremes of the Jersey breed. It is proposed to subject 

 the pedigrees of these bulls in each of these lists to a careful 

 analysis of their inbreeding and relationship. The formulae 

 and methods of calculation of these variables have been 

 discussed on page 102 of this paper. The Z l5 Z, and Z 3 of 

 tables 10 and 11 stand respectively for the second, third, and 

 fourth generations inbreeding coefficients. The Z T? stands 

 for the amount of inbreeding which has taken place as com- 

 pared with the total possible amount. The K 2 , K 3 and K 4 

 stand for the degree of relationship which exists in the pedi- 

 gree of the second, third and fourth generation respectively. 

 The figures given for the sires Golden Glow's Chief, Channel 

 King, Spermfield Owl, Sultan of Oaklands, Mabel's Raleigh, 

 Blue Belle's Golden Fern, and Eminent 4th are not entirely cor- 

 rect as the pedigrees of these bulls are not complete since they 

 run into foundation stock. 



Besides this analysis, the pedigrees were studied to deter- 

 mine the amount of Island bred Jersey ancestry which each of 

 these sires had. This was classified in two ways ; as the number 

 of island bred males occurring in the sire's side of the pedigree 



