His club career had seen him play for Cambridge University,[4] London Scottish[5][6] and King's College Hospital.

[8] MacMyn made his international debut on 24 January 1925 at Inverleith in the Scotland vs France match.

[2] In 1927, he was chosen to captain the British and Irish Lions tour to Argentina which was won by four Tests to nil.

In 1932 he obtained a Rockefeller Travelling Fellowship in surgery, and he studied neurosurgery at the Mayo Clinic.

He returned to London eighteen months later and having had difficulty in qualifying for the FRCS, he accepted a partnership in a West End general practice, abandoning a career in neurosurgery.

After his military career during and just after the Second World War, he joined his father in his long-established general practice at Kirkcudbright.

By September 1939 he had reached the rank of major and at the beginning of the Second World War was posted to a field ambulance in the 52nd (Lowland) Division, which he commanded soon afterwards.

[3] MacMyn was known to enjoy a number of hobbies including golf, troutfishing, rereading the classics, and his garden, in which he grew roses that were much admired.

In addition, his association with rugby never waned and even after a slight stroke in December 1976 he accompanied a Scottish touring team to Japan in July 1977.

Note 9: Michael Owen captained the Lions in the first tour game, the test vs. Argentina in Cardiff.