SummaryThe anatomical relationship between the corpora allata (CA) and the neurosecretory cells of the honeybee brain was studied using the cobalt chloride technique for filling axons and cell bodies. The neurosecretory system contains 3 major cell groups that have axonal connections to the CA. The medial group contains on the average 28 cells with axonal connections to a single CA. There are 2 lateral groups; mean cell numbers are 7 and 4 in Group 1 and Group 2, respectively. Ramifications of the axons leading to Group 2 extend across the brain to the midline. The honeybee is similar to other insects with respect to the anatomy of its neurosecretory system. No differences in morphology were noted between workers and a small sample of queens.