The object of this experiment was to find out whether ground supplements could be conveyed to the abomasa of sheep via the reticular grooves. If ruminal fermentation could be avoided in this way, suitable supplements would be more efficiently utilized. The flowpaths of the supplements in the stomachs were followed in two ways. Firstly about half of the contents of a rumen was removed through the large rumen fistula. In this way the reticular groove could be observed. When supplements of 98 g of maize meal plus 2 g NaCl were ingested the grooves were seldom functional). The second method involved following the flowpaths of marked supplements in the stomachs of sheep fitted with rumen and abomasal cannulae. The soluble fraction of a supplement was marked with the soluble marker 51Cr-E (Cr complexed with ethylenediaminetetra – acetic acid) . The contrasting coarse particles were marked with the particulate marker l03Ru-P (tris (1,l0 – phenanthroline) Ru (lII) chloride). Sheep were offered chopped wheaten hay ad lib. And marked supplements similar to the one above. Two flowpaths were followed. Normally a supplement was ejected through the cardia. Cr-E became associated with the water fraction of the reticulo-rumen digesta. The marked maize particles by contrast (that had an S.G. of 1,45) sank to the bottom of this digesta. On a few occasions the reticular groove was activated. A supplement was then conveyed directly to the abomasums. Our present knowledge does not permit us to compile a dry supplement which will consistently activate this groove.