We present the first clear evidence of the occurrence of the modified two stream (Farley-Buneman) instability and excitation of pure type 1 irregularities in the midlatitude ionospheric E region. The observations are made with a bistatic 50-MHz Doppler radio experiment set up recently in Crete, Greece. The system can perform high-frequency resolution coherent backscatter measurements along a fixed direction, from 3-m magnetic aspect sensitive irregularities inside a limited ionospheric volume in the E layer at the invariant geomagnetic latitude of 30.8¿ (L=1.35). The observations presented here are from an event of backscatter characterized by large Doppler motions caused, presumably, by an impulsive electric field reaching a magnitude at least 14 mV/m. Apparently, the unusually high electron drifts along the radar viewing direction were sufficient in this case to excite pure Farley-Buneman waves. This had been manifested convincingly by the measured power Doppler spectra, which are reminiscent of the typical spectral signature of type 1 echoes observed regularly in the equatorial 50-MHz backscatter. Further, the spectral data confirmed the anticipation that in the midlatitude E region plasma exist two irregularity types corresponding to those of type 1 and type 2 echoes in the equatorial electrojet. The important difference with the equatorial results, however, is that the threshold conditions for the two-stream instability are seldom met at moderate latitudes, thus the medium is highly suitable for studying secondarily generated short-scale plasma turbulence. ¿ American Geophysical Union 1994