26 BULLETIN 1222, U. S. DEPARTMENT OF AGRICULTURE. 



An entrance to the hive was gained by means of a maze tunnel 

 leading through the wall of the room which excluded all light. The 

 bees traveled in total darkness for a distance of approximately 6 

 inches before entering the hive proper. 



The reason for placing this hive in a dark room was that when 

 bees are kept in an observation hive out of doors they tend to con- 

 gregate on the glass and thus hide the activities of the nurse bees 

 to too great a degree for such observations. It was found that this 

 does not occur when bees are kept in such a hive in a dark room for 

 a considerable period. 



The hive used was of standard 10-frame dimensions, containing 

 10 drawn combs which previously had been used for rearing brood. 

 Several of these combs contained brood when placed in the hive 

 and some of the combs contained sealed honey above the brood. The 

 colony was of average strength for a colony kept in a single hive 

 body. During the course of the observations the worker bees ap- 

 parently flew in normal numbers to the field. Supplies were col- 

 lected and brood was reared in numbers that justify the statement 

 that the behavior of the bees, both workers and queen, was approx- 

 imately normal. The observations extended from August 25 to 

 September 9, 1922, during which period little nectar was coming in. 

 A small amount of sirup was given once. 



Various arrangements of electric lamps were tried so as to secure 

 the best lighting, but best results are obtained by using a 40-watt- 

 lamp, which is placed on the top of the hive and back from the 

 edge far enough to exclude all direct rays from the comb. A mirror 

 attached to a flexible support is then adjusted so that the rays from 

 the lamp are reflected to the portion of the comb under observation. 

 The hive is slightly above the level of the eyes, and when the eyes 

 are placed just behind and a little below the mirror an excellent 

 view of the interior of the cell is obtained. A concave mirror is 

 best for close inspection of the contents of a cell, while a small 

 plane mirror is best for ordinary observations. Shades are attached 

 to the sides of the mirror to protect the eyes from direct light from 

 the lamp. 



Under normal conditions in a hive containing a number of combs 

 the brood nest is in the inner combs, and this makes impossible 

 observations of what takes place during feeding. To obviate this 

 difficulty, combs containing larvae of the desired age were taken from 

 the center of the brood nest and placed next the glass. The hive 

 was well filled with bees of all ages, and at once the nurse bees 

 appeared and took up their duties as attendants on the outside of 

 the comb, where their activities could be observed readily. 



On one occasion all brood was removed from the hive and empty 

 combs partially filled with sirup were put in. A single frame of 

 brood of the desired age was then placed in the hive next the glass. 

 On this occasion the queen appeared on the outside of this comb, 

 where she remained for one hour. During this period she laid a 

 number of eggs, rested, and was fed, in a manner suggesting normal 

 conditions. Several flashlight pictures of the laying queen were 

 taken, but even these flashes failed to drive her to the other side of 

 the comb. 



The cells to be studied are either marked before the comb is placed 

 in the hive or selected by a close study with the concave mirror after 



