I don't see in the book where it says that.



In this google book, the Akkadians were called "black-headed" people, not the Sumerians:

[link to books.google.com]

The sculptures of this period distinguish sharply between the ethnological types of the Sumerians and Akkadians. The Sumerians shaved their heads and their faces, while the Akkadians wore long hair and full beards and mustaches. Hence the phrase "black-headed ones" originated in this period as a description of the Akkadians in contrast to the Sumerians. Semitic kings say that the gods have given them sovereignty over the "black-headed ones".