Abstract: Textile strand stabilization by filament interlacing is provided by means of jet apparatus having a longitudinal strand-receiving bore intercepted by at least one fluid-receiving bore substantially perpendicular thereto and to its minor transverse axis. Fluid injected into the fluid-receiving bore establishes within the longitudinal bore a vortex-like flow configuration substantially perpendicular to the longitudinal axis and to the minor transverse axis of the longitudinal bore. The apparatus preferably has a plurality of fluid-receiving bores offset along the longitudinal axis by distances up to the width of a fluid receiving bore.