THE BROOD-REARIXG CYCLE OF THE HONEYBEE 3 
The first trustworthy determination of the number of eggs laid 
in a single day was made by von Berlepseh (J, pp. 68-69) in 1856. 
Having succeeded in confining the egg-laying activity of an especially 
prolific queen to a single comb for 24 hours, he found that mean- 
while 3,021 eggs had been laid. An estimate of the amount of 
brood remaining in the hive to which the queen belonged led to the 
assumption that she had been averaging nearly 3,000 eggs daily for 
the preceding 20 days. During the remainder of the nineteenth 
century this rate was widely accepted as a proper index of a queen's 
daily egg-laying capacity, although von Berlepseh himself believed 
such a rate to be exceptional, and that a daily average of only 1,200 
is probably usual. Inasmuch as this particular queen was active 
for five seasons, von Berlepseh assumed that she must have laid at 
least 1,300,000 eggs during her lifetime, a number which apparently 
has served many later writers as a basis for their estimates of the 
total possible egg-laying achievement of a queen. Baldridge (2), an 
American contemporary of von Berlepseh, deserves mention because 
he furnished the first published census of all the eggs, larvoe, and 
sealed brood in a modern hive, determined by an actual count. 
He even entertained the idea of counting all the eggs in a certain 
colony every 72 hours, but apparently never carried it into effect. 
The first authentic data as to the total number of eggs laid by a 
cjueen throughout an entire season were published by Desborough 
in 1852 (8). In 1855 (9) he published data in regard to the number 
of eggs laid by one queen in two successive seasons, and in 1868 (10) 
he presented similar data covering six successive seasons for a single 
queen. Desborough's figures were obtained by making periodic esti- 
mates of the area occupied by brood. The colony used seems to have 
been so much below normal strength, however, that his findings can 
not be taken as typical. For the next 40 years, of the many reports 
on the quantity of brood found in a hive, or of the daily egg-laying 
capacity of a queen, few are of any real value in understanding the 
annual brood-rearing cycle. Interesting as they may be, these 
reports too often represent only the performance of some exceptional 
queen during a single day at the height of the season. Such sporadic 
endeavors, either in themselves or in relation to other similar reports 
from localities under far different conditions, afford little basis for 
drawing conclusions as to brood-rearing activity throughout a whole 
season. Although during this long stretch of years it may have been 
realized that the annual brood-rearing cycle can be determined only 
by continuous observations on the same colonies during any given 
season, apparently no one undertook the task. Finally, in 1895, 
Baldensperger (1) furnished the first published results of successive 
counts or estimates throughout the year of the quantity of brood in 
a colony of normal strength. 
An epoch in this line of research is marked in 1901. when 
Dufour (11) published data obtained from the first comprehensive 
study of the subject by a scientific method of approach. As a 
result of four years' work he had secured seven seasonal brood- 
rearing records by actually counting, at intervals of approximately 
21 days throughout each season, every egg, larva, and sealed brood 
cell in each colony used. In 1912, the first seasonal curves based on 
results from brood-rearing investigations were presented by Bri'in- 
nich (4). In 1919 (J), and again in 1922 (6), he presented other 
