THE BROOD-BEARING CYCLE OF THE HONEYBEE 3 



The first trustworthy determination of the number of eggs laid 

 in a single day was made by von Berlepsch (3, 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 Berlepsch 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 Berlepsch 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 Berlepsch, deserves mention because 

 he furnished the first published census of all the eggs, larvae, 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 

 queen 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 

 re ult of four years' work he had secured seven seasonal brood- 

 rearing records by actually counting, at intervals of approximately 

 2f days throughout each season, every egg, larva, and sealed brood 

 cell in each colony used. In 1012, the first seasonal curves based on 

 results from brood-rearing investigations were presented by Brun- 

 nich (4). In 1919 (5), and again in 1922 (6), he presented other 



