In a former chapter I have described the happy little family in Central Park, which consisted of the five little brown cousins, only a few months ago; but death has reduced their number to two. In this connection I shall mention a very important fact concerning the use of the natural senses of these animals. I have several times been assured that monkeys depended more upon their sense of smell than upon that of sight as a means of recognition, and that in this respect they were very much like the canines. I have made frequent tests of the power of their senses, and am prepared to say with certainty that such is not the case. When I visit the Park, I frequently enter at Sixty-fourth Street and Fifth Avenue, at which place there is a flight of stairs leading from the street down to a large plazza in front of the Old Armoury; and something more than a hundred feet from the foot of the stairway, and nearly at right angles to it, is a window opening into the monkey-house by the cage occupied by these particular monkeys. When I descend the stairway and come within view of this window, they frequently see me as I reach the plazza, and the keeper always knows of my approach by the conduct of the monkeys, who recognise me the instant I come in sight at that distance. At other times I have approached the house from another direction, and come within a few feet of their cage, where I have stood for some time, in order to ascertain whether they were aware of my presence; and on a few occasions have slipped into the house with the crowd, and they did not detect my presence except by sight. It is evident, if they depended upon the sense of smell, that they would have discovered my presence when so near them, although they could not see me. But no matter what the condition of the weather, or how many people are present, the instant one of them sees me he spreads the news, and every inmate of the cage rushes to the window and begins to scream at the top of his voice. If their sense of smell was such as to enable them to detect my presence as a dog would, it is reasonable also that the monkey which possessed the most sensitive organs would have been the first to detect it in each case; whereas, sometimes one monkey, and sometimes another, made the discovery. It is my belief, however, that their sense of smell is much more acute than that of man, but far less so than that of most other animals, especially the dog. [Sidenote: HEARING VERY DELICATE] The sense of hearing in these animals is very delicate, as may be seen from the account of Nellie discovering my footsteps on the lower stairway, and as I have witnessed in scores of other cases. The same is true also of their sight; their eyes are like a photo-camera, nothing ever escapes them. I think their organs of taste are also quite sensitive, as I have made some tests from time to time, and find them very hard to deceive. The sense of touch, which is rather obtuse in most animals, is much more acute in these.