Morgan worked with the tiny fruit files,called Drosophila melanogaster,very suitable for such studies, as :

$(i)$ They could be grown on simple synthetic medium (ripe banana) in the laboratory.

$(ii$) They could be grown on simple synthetic medium (ripe banana) in the laboratory.

$(iii)$ They complete their life cycle in about two weeks.

$(iv)$ A single mating could produce a large number of progeny flies.

$(v)$ There was a clear differentiation of the sexes(sexual dimorphism) -the male and female flies are easily distinguishable.

$(vi)$ It has many types of hereditary, variations that can be seen with low power microscopes.