He also visited the United States during this period, looking at agricultural entomology and meeting people such as T. H. Morgan, a close associate of Bateson.
[1] During World War I he trained in the London School of Tropical Medicine, to assist the Royal Army Medical Corps in identifying pathogenic bacteria and spent most of his time in that unheroic branch of warfare, examining the stools of dysentery patients.
Williams dedicated his book on Patterns in the balance of nature to his wife in gratitude for her wisdom in the art of living.
[1] In 1921 Williams returned to England and here he accepted a post in the Entomological Section of Egypt’s Ministry of Agriculture.
His work in Egypt was mostly administrative but he was able to study some further aspects of insect migration as they applied to economic entomology.
In 1929 he went home on leave with the intention of returning to East Africa but he accepted the offer of the Steven lectureship in Agricultural and Forest Entomology in the University of Edinburgh.
in 1930 from Cambridge University with a thesis on "Migration of Butterflies"[2] In Africa, Williams met Reginald Ernest Moreau, who was an accountant in Egypt with an interest in birds.
Moreau later became a pioneer who developed theories on life-history, influencing David Lack with his studies on clutch size in birds.
Russell had earlier invited R. A. Fisher and Williams was able to study quantitative aspects of insect populations.
[6] With Fisher, Williams was able to establish patterns in the diversity and numbers of insects caught in light traps.