South African Biological Association Pamphlet No. 19: 47, 1957.
A column entitled The Valuable Amateur: includes the following note:
Dr. G. van Son, entomologist at the Transvaal Museum, Pretoria, is an amateur botanist whose special avocation is the cultivation of orchids, indigenous and exotic. His orchid houses provide Pretoria with a show place. Not only are the blooms a grand sight - it is interesting to learn the involved process by which they are propagated and all that the growing of orchids entails. Film Services have availed themselves of the opportunity and have made an educational film in the orchid houses with Dr. van Son demonstrating his methods.