Alexander was born about 1850. He is the son of John Sellar and Jane Stephen.
<https://www.findmypast.co.uk/transcript?id=GBC/1851/0019032951>
<https://www.findmypast.co.uk/transcript?id=GBC/1861/0022070455>
<https://www.findmypast.co.uk/transcript?id=GBC/1881/0026266873>
<https://www.findmypast.co.uk/transcript?id=GBC/1891/0032165544>