Basic morphometric parameters of melanosomes isolated from mouse hair, hamster eye and hamster hair are given and tabelized with those published formerly to enlarge the widest published collection of melanosomes isolated from different types of pigmented tissues up to 17 types. The splitting of melanosomes isolated from mixed tissue of hamster eyes into two subpopulations confirmed the presence of double origin of melanosomes in the eye. The close correspondence of subpopulations of hamster eye melanosomes with hamster hair and hamster melanoma (type Bomirski) respectively supports the hypothesis of high structural stability of melanosomes even under pathological conditions.