Three or four different correspondents tell me of cases which they have themselves observed, of snakes and tortoises unmistakably distinguishing persons. In one of these cases the tortoise would come to the call of the favoured person, and when it came would manifest its affection by tapping the boot of this person with its mouth; 'but it would not answer anyone else.' A separation of some weeks did not affect the memory of this tortoise for his friend.[138] The following interesting observation on the intelligence of snakes shows, not only that these animals are well able to distinguish persons, and that they remember their friends for a period of at least six weeks, but also that they possess an intensity of amiable emotion scarcely to be expected in this class. Clearly the snakes in question were not only perfectly tame, but entertained a remarkable affection for those who tended and petted them. The facts were communicated to me by Mr. Walter Severn, the well-known artist, who was a friend of Mr. and Mrs. Mann, the gentleman and his wife to whom the snakes belonged. Mr. and Mrs. Mann having got into trouble with their neighbours on account of the fear and dislike which their pets occasioned, legal proceedings were instituted, and so the matter came before the public. Mr. Severn then wrote a letter to the _Times_, in order to show that the animals were harmless. From this letter the following is an extract:-- I happen to know the gentleman and lady against whom a complaint has been made because of the snakes they keep, and I should like to give a short account of my first visit to them.