308 
explanation can be finally accepted, 
however, more work on the relation of 
the different monthly lactations needs 
to be done. 
The eight months milk production 
of Crossbred No. 2 was 5337.2 pounds. 
The milk yield of Canada’s Creusa 
was 3608.5 pounds and that for Delva’s 
University De Kol was 5548.9 pounds. 
In other words Crossbred No. 2 was 
within 221.7 pounds of milk of her 
high producing parent and was 1728.7 
pounds of milk more than her low 
producing parent. The Crossbred No. 
2 was, therefore, 7.8 times as close to 
the high line as she was to the low line. 
This fact in connection with the mill 
record of Crossbred No. 1 suggests 
that segregation of milk producing 
factors having dominance has taken 
place in these crosses. 
The milk production of Crossbred 
No. 11, shown as the third graph of 
Fig. 14,is clearly intermediate between 
that of her dam Delva Johanna De 
Kol 146774 and her sire Lakeland’s 
Poet 102603 for the first four months 
of lactation. From this time on this 
cow follows closely the milk produc- 
tion of the high milking parent Delva 
Johanna De Kol. The crossbred rec- 
ord consisted of the average of three 
corrected records; that of the Holstein- 
Friesian dam consisted of the average 
of eight corrected records; that of the 
sire consists of the average of four pure 
bred daughters for two lactations each. 
The photographs of this mating are 
given in the succeeding paper of this 
series. 
The records of Crossbred No. 11 all 
commenced in the months of July and 
August. As previously pointed out 
the calving in these months is most 
unfavorable to a high record, so un- 
favorable as to make a difference of 
600 pounds of milk in the eight months 
milk record of Jersey cows. Whether 
this explanation will account for the 
milk yield of Crossbred No. 11 being 
intermediate between that of the high 
and low lines during the first four 
months of lactation is not known; al- 
though it is highly probable that the 
time of calving did have some effect 
The Journal of Heredity 
toward reducing the yield. With the 
dam this time of calving effect on the 
milk yield of the lactation is approxi- 
mately averaged as she calved three 
times in the month of April, twice in 
the month of March, and once in the 
months July, June and May. Like- 
wise the record for Lakeland’s Poet is 
approximately averaged although fa- 
voring somewhat the high side of the 
milk production as his daughters calved 
three times in April, twice in February 
and once in May, November and Jan- 
uary. 
The eight months milk yield of 
Crossbred No. 11 was 4984.8 pounds, 
that of Delva Johanna De Kol was 
5375.8 pounds, and that of Lakeland’s 
Poet was 3919.0 pounds. Crossbred 
No. 11 w s consequently 391.0 pounds 
of milk below the milk yield of her 
high milk line, ancestrally speaking, 
and 1065.8 pounds of milk above the 
low milk line. The crossbred cow is 
consequently 2.7 times as near the high 
line of milk yield as she is near the low 
line of milk yield. 
The fourth graph of Fig. 14 shows the 
milk yield of Crossbred No. 12 and her 
two parents. The photographs of this 
crossbred and her purebred parents are 
seen in Figs. 8, 9 and 10. This cross- 
bred’s milk record clearly follows the 
high milking parent throughout most 
of the course of the lactation. As in 
the preceding cross there is some slight 
indication that the crossbred tends to 
be intermediate between the two lines 
for the first few months of lactation. 
Her calving dates were on the whole 
such as to neutralize any time of year 
effect on milk yield. Likewise the 
records of the sire and dam show little 
of this effect. 
The eight months lactation record of 
Crossbred No. 12 was 5367.3 pounds; 
the record of her Guernsey dam, Col- 
lege Gem was 2693.5 pounds; the po- 
tential record of her Holstein-Friesian 
sire, Taurus Creamelle Hengerveld, 
5548.9. Crossbred No. 12 is conse- 
quently 2693.5 pounds of milk more 
than her Guernsey dam and 181.6 
pounds of milk less than her Holstein- 
Friesian sire or her high parent. The 
