232 
GENETICS: R. PEARL 
Proc. N. a. S. 
daughters over that of their dams. The sires which raised the produc- 
tion of their daughters' butter-fat most were Sans Aloi 81012, Signal's 
Successor 72758, and Golden Glow's Chief 61460. The sires which made 
the deepest impress on the breed by raising the butter-fat of the largest 
number of daughters over that of their dams was Hood Farm Torono 
with 34 pairs and an average increase for each daughter of 121.51 pounds 
of butter-fat. The next bull, Spermfield Owl, with 26 pairs raised tlie 
butter-fat production 97.71 pounds on the average for each of his daughters. 
Some of the bulls lowering the production of their daughters markedly 
were Gertie's Son of Washington 83799, Hood Farm S. Tormentor 96311, 
and Oxford Lad's Owl 75599. 
5. The information summarized above was arranged to reveal the trans- 
mitting qualities for milk production, butter-fat percentage and butter- 
fat of Jersey sires to their sons. There were 159 sires which had sons 
whose progeny performance was known. Of this number 69 or signifi- 
cantly less than half had sons who raised the butter-fat production of their 
daughters over that of their dams. 
6. The sires of superior merit are defined as those which raise the milk 
production and butter-fat percentage of their daughters as compared with 
that of their dams. The inferior sires are defined as those sires who lower 
the milk production and butter-fat percentage of their daughters as com- 
pared with the same variables in their dams. The superior sires so de- 
fined were arranged by the amount of butter-fat that they increase the 
production of their daughters over that of their dams. The inferior sires 
were classified according to the amount of butter-fat that they decrease 
the production of their daughters in comparison with that of their dams. 
These two groups of sires are subjected to four generation pedigree analysis 
to determine their inbreeding and relationship, the amount of Island and 
American stock, "males and females" and "on the sire's side of the pedigree 
and on the dam's side of the pedigree," and the individual animals most 
frequently repeated into two groups of pedigrees. 
7. There are 28 sires in the group of sires superior in their transmitting 
qualities for milk production and butter-fat percentage. In the group 
of sires inferior in their transmitting ability for these two characters there 
are 47 sires, a ratio of 1 to 1.7. Such a difference speaks for itself. It 
emphasizes with startling clearness the need of exact knowledge of the 
transmitting qualities of bulls to be bred as sires and of the necessity for 
exact knowledge of the inheritance of milk production and butter-fat 
percentage. 
8. The inbreeding coefficients show that the sires of superior merit have 
7.08 % of the greatest possible inbreeding up to the fifth generation. The 
inferior sires are inbred 9.65% of the greatest possible amount (continued 
brother and sister mating). The group of sires poorer in their transmitting 
