April, ’23] 
NOLAN: TWO-YEAR BROOD CURVE 
123 
in 1922, had already been used for nectar and pollen coming in during the 
period between this break and the peak. When the maximum was 
reached, tulip-trees were yielding and many cells in the brood-nest 
proper were being used for nectar. Due to these circumstances the 
queen was partially restricted in egg-laying for several days, and in 
consequence the brood curve for 1921 drops from its maximum more 
sharply at first than is the case in the curve for 1922. Consumption or 
removal of the nectar in the brood area soon gave the queen more room, 
which she promptly used, thus making the curve at this point compara¬ 
ble again to that of 1922. The second cause of the more pronounced 
upward break of the curve during June, 1921, is due to the fact that 
associated with the incoming pollen of this month there was an ex¬ 
ceptionally large amount of honey dew available, and also nectar from 
sweet clover in appreciable quantities. During both years the curves 
for the remainder of the summer decline follow courses almost parallel 
until the beginning of the final phase is reached in August. At the end 
of each season’s second phase brood-rearing activity had been reduced to 
a point only one-third as great as that represented by the maximum for 
the same year. 
The third, or final phase, is the one which may spell success or failure 
for the first phase of the succeeding year, because during it the young 
bees emerge which winter over and determine the amount of brood 
which can be cared for in early spring. In both 1921 and 1922 two minor 
peaks occurred during this final phase. The first of these represented a 
very intense pollen yield, and the second the fall nectar flow. After the 
latter peak there was a rapid decline until - brood-rearing ceased com¬ 
pletely. All in all, except for minor deviations due to differences in 
weather conditions, the curves of this colony during the two successive 
years present striking similarities. 
In neither of these seasons did the queen approach any such rate as 
found by von Berlepsch in his experiment covering only twenty-four 
hours. For the colony to produce the total amount of sealed brood 
found in the hive during 1921, it was necessary for the queen to lay 
202,830 eggs during the season, or an average of 905+ daily for 224 
days. The total amount of sealed brood in 1922 represents 213,076 
eggs, or an average of 895+ daily for 238 days. Although the total for 
1922 is larger than for 1921, yet the average daily egg-laying rate is 
lower because the season in 1922 lasted 34 weeks instead of only 32 
weeks as in 1921. The highest daily rate during any 12-day period in 
1921 was 1488, while the highest daily rate during any similar period in 
