In most cases the individuals which failed to return to their respective scars took up new positions; and in several instances, when they were subsequently removed to a distance of a few inches from this new position, they returned to it. Their return to the scar was watched in many cases, and the course was fairly, but not quite direct. One limpet covered a distance of ten inches, over a somewhat curved course, in a little under twenty minutes. In another case the limpet on its return journey had to pass between two others, which necessitated the lifting of the shell to some height so as to clear one of them. On reaching the scar they twist and turn about so as to fit down in the normal position which is constant. When they come up the wrong way round they rotate pretty rapidly through the 180 degrees to get into position. One was observed to make a short excursion from and return to its scar under stillish water. But as a rule they seem to remain fixed when they are submerged, moving for the most part when the tide has just receded. The greatest distance I have watched a limpet reach from its home was twenty-two inches. But I have found them at a distance of three feet from their scars--that is to say, from those to which they fitted perfectly. This was on a large flat surface. When they move, the tentacles are projected out beyond the shell, and keep on touching and slightly adhering to the rock. On reaching the scar they carefully feel round it with the tentacles. By excision of these feelers Professor Davis was led to conclude that it is not through their instrumentality that the limpet finds its way back to its particular scar. But I am inclined to question these results. At any rate, further observations and experiments are needed to settle the point. Snails will also return to special dark hollows or crannies in the wall after their foraging excursions. Such behaviour in molluscs affords evidence of something more than instinct. In popular speech, we should say that there is memory of the locality. And in any case it is difficult to interpret the facts without the assumption that the animals are conscious, and that re-presentative states are evoked through the mediation of presentative sense-impressions. But how difficult, if not impossible, it is to form anything like a satisfactory conception of the rudimentary mental processes of a limpet!