part_of larval development moulting secretion of moulting hormone IDOMAL:0002169 IDOMAL:0002169 The hormone from the neurosecretory cells of the brain activates the thoracic glands and causes them to secrete the moulting hormone. The thoracic glands requie the continued presence of the brain hormone until the "critical period", when mitosis has begun and there is an adequate supply of moulting hormone in the blood. idomal_namespace