A neuro-anatomical investigation into the thalamic reticular nucleus and its connections was made in the albino rat, using the method of retrograde degeneration and the Nauta-Gygax method. The results correspond to the description given by Scheibel and Scheibel and indicate connections of the neurons of the reticular which the principal thalamic nuclei and the rostral part of the intralaminar thalamic nuclei. A topographical arrangement of the efferent connections of the reticular nucleus is demonstrated. The projection of the reticular nucleus upon the thalamus duplicates the cortico-thalamic connections.