P862:5, 77:6.1 While the primary midwayers had a well-nigh superhuman origin, the secondary order are the offspring of the pure Adamic stock united with a humanized descendant of ancestors common to the parentage of the senior corps.
P862:6, 77:6.2 Among the children of Adamson there were just sixteen of the peculiar progenitors of the secondary midwayers. These unique children were equally divided as regards sex, and each couple was capable of producing a secondary midwayer every seventy days by a combined technique of sex and nonsex liaison. And such a phenomenon was never possible on earth before that time, nor has it ever occurred since.
P862:7, 77:6.3 These sixteen children lived and died (except for their peculiarities) as mortals of the realm, but their electrically energized offspring live on and on, not being subject to the limitations of mortal flesh.
P862:8, 77:6.4 Each of the eight couples eventually produced 248 midwayers, and thus did the original secondary corps -- 1,984 in number -- come into existence. There are eight subgroups of secondary midwayers. They are designated as A-B-C the first, second, third, and so on. And then there are D-E-F the first, second, and so on.
P862:9, 77:6.5 After the default of Adam the primary midwayers returned to the service of the Melchizedek receivers, while the secondary group were attached to the Adamson center until his death. Thirty-three of these secondary midwayers, the chiefs of their organization at the death of Adamson, endeavored to swing the whole order over to the service of the Melchizedeks, thus effecting a liaison with the primary corps. But failing to accomplish this, they deserted their companions and went over in a body to the service of the planetary receivers.
P863:1, 77:6.6 After the death of Adamson the remainder of the secondary midwayers became a strange, unorganized, and unattached influence on Urantia. From that time to the days of Machiventa Melchizedek they led an irregular and unorganized existence. They were partially brought under control by this Melchizedek but were still productive of much mischief up to the days of Christ Michael. And during his sojourn on earth they all made final decisions as to their future destiny, the loyal majority then enlisting under the leadership of the primary midwayers.