Thomas Morgan first used milk bottles to sex linked trait in fruit flies his fly cultures. And yes, he did get the bottles from his milkman. Although Mendel had no trouble finding pea plants with lots of different traits, it took a while for Morgan to find a fly with a different trait. In 1904, I started the “Fly” lab at Columbia University to study genetic variations.
Many of the important discoveries of genetics and chromosomal inheritance came out of my lab through research using fruit flies. It all started when we found our first useful fruit fly mutation. Flies normally have red eyes but in January, 1910, we found a male with white eyes. Funded by The Josiah Macy, Jr.