[…]phonetically spelt-just according to how it sounds to him, and we have not attempted to worry him with orthography! His own original remarks are delightful. The dog, Rolf, attained in the course of time to a higher level than did the horses. This may probably be explained by the fact that dogs are, as a rule, more continuously in the company of human beings, being also due to their superior intelligence. Rolf’s mode of procedure consisted in a series of raps given with his fore-paws, similar to those given by the horses with their hoofs; but Rolf used the same paw for both decimals and units, so that we had from time to time to inquire after every number rapped out-‘Is it a decimal or a unit?’ Whereupon[…].