Reticulin has been classically identified by virtue of its argyrophilia, as observed by light microscopy. The similiarity between reticulin and collagen has been a matter for considerable discussion. This paper describes the application of a silver-staining procedure which demonstrates the fine structure of these fibres when studied by electron microscopy, giving a direct indication of the morphological identity of the argyrophilic structures, i.e. reticulin, with collagen. Beef lymph node tissue was used for this study.