The desert Arabs form a group of considerable anthropological interest. The only studies on them which include blood group data, however, are those of Shanklin ( '35, '36), and Kennedy and MacFarlane ( '36). In the latter paper only a few results on desert Arabs are given, and none of these studies included the M,N types. So there seemed to be room for further work in this connection.
I n 'Iraq there are a number of Arab tribes which are either only recently settled down to the land, or are in the process of doing so. These afford a valuable opportunity to the physical anthropologist, which should, however, be utilized before these interesting racial groups lose their identity, due to mixture with other groups and with each other. We were able during the autumn of 1937 to study the blood groups of over 300 of these Arabs. ' We took specimens from four different localities near Baghdad: 1) Khan en Noqta, west of Baghdad, where members of the Zowba' tribe were examined, 2) Aqar Qiif, northwest of Baghdad, where we examined the Beni T a d , 3) Mahmfidiya, south of Baghdad, where we obtained a mixed group, mostly Dul6m and Ghrgr, and 4) Ba'qiiba, northeast of Baghdad, where the subjects were mostly Dulgm, 'Azah, and Beni Tamim. These different groups of subjects will be afterward designated as I, 11, etc.
The bloods were sometimes taken in the morning and tested the same afternoon, and sometimes taken in the afternoon, kept on ice overnight, and tested the next morning. The technic of testing was as described by Landsteiner ('29).