But, without denying that conscious determination may here be present, or involving ourselves in the impossible task of proving such a negative, we may properly affirm that until an animalcule shows itself to be teachable by individual experience, we have no sufficient evidence derived or derivable from any number of such apparently intelligent movements, that conscious determination is present. Therefore, I need not wait to quote the observations of the sundry microscopists who detail facts more or less similar to the above, with expressions of their belief that microscopical organisms display a certain degree of instinct or intelligence as distinguished from mechanical, or wholly non-mental adjustment. But there are some observations relating to the lowest of all animals, and made by a competent person, which are so remarkable that I shall have to quote them in full. These observations are recorded by Mr. H. J. Carter, F.R.S., in the 'Annals of Natural History,' and in his opinion prove that the beginnings of instinct are to be found so low down in the scale as the Rhizopoda. He says:--'Even _Athealium_ will confine itself to the water of the watch-glass in which it may be placed when away from sawdust and chips of wood among which it has been living; but if the watch-glass be placed upon the sawdust, it will very soon make its way over the side of the watch-glass and get to it.' This is certainly a remarkable observation: for it seems to show that the rhizopod distinguishes the presence of the sawdust outside the watch-glass, and crawls over the brim of the latter in order to get into more congenial quarters, while it is contented with the water in the watch-glass so long as there is no sawdust outside. But to proceed: