William Hewson wrote ‘The thymus gland we consider as being an appendage to the lymphatic glands, for the more perfectly and expeditiously forming the central particles of the blood of the foetus, and in the early part of life. We have proved that vast numbers of central particles made by the thymus and lymphatic glands are poured into the blood vessels through the thoracic duct and if we examine the blood attentively we see them floating in it.’

Cited by Doyle D, Brit H Haematol 133:375-381, 2006

International Union of Immunological SocietiesUniversity of South AfricaInstitute of Infectious Disease and Molecular MedicineElizabeth Glazer Pediatric Aids FoundationStellenbosch University