mˈɔːɹɡən bᵻlˈiːvd ðə pɹˌiːhɪstˈɔːɹɪk stˈeɪdʒᵻz æz dᵻfˈaɪnd baɪ ðə dˈeɪnɪʃ wɜː dˈɪfɪkəlt tə dɪstˈɪŋɡwɪʃ, æz ðeɪ ˌoʊvɚlˈæpt ænd ɹᵻfˈɜːɹ ˈoʊnli tə mətˈɪɹiəl tˈaɪps ʌv ˈɪmplɪmənts ɔːɹ tˈuːlz.
Morgan believed the prehistoric stages as defined by the Danish were difficult to distinguish, as they overlapped and refer only to material types of implements or tools.