The purpose of this study is to correlate in detail auroral activity with the corresponding disturbances in the magnetotail. The auroral data were recorded by optical instruments aboard an airplane flying over the Arctic Ocean along the Alaska meridian and by the Alaska meridian chain of all-sky cameras. The corresponding magnetotail observations were made by various instruments on Vela 6A and Imp 5; the interplanetary magnetic field was monitored concurrently by Explorer 35 (Imp E). Three successive substorms were observed on February 17, 1971. Each substorm was readily identified by the classical auroral and magnetic signatures which accompanied its onset. The observed variations of plasma and magnetic field in the magnetotail were consistent with the idea that a neutral line formed in the range ~-12 RE>XSM>-18 RE at the onset of each substorm expansive phase and then moved tailward past XSM=-18 RE some tens of minutes afterward. The Z component of the tail magnetic field decreased rather steadily for a period of 1--21/2 hours after each substorm and until the onset of the next expansive phase, reaching a minimum value just before each onset. This taillike development of the field is more appropriately regarded as the normal evolutionary pattern of variation between substorms than as a 'growth phase' preceding each substorm.