“Frowning, which is one of the most important of all the expressions in man, is due to the contraction of the corrugations by which the eyebrows are covered and brought together, so that vertical furrows are formed on the forehead. Both the Orang and Chimpanzee are said to possess this muscle, but it seems rarely brought into action, at least in a conspicuous manner. I made my hands into a sort of cage, and placing some tempting fruit within, allowed both a young Orang and Chimpanzee to try their utmost to get it out; but, although they grew rather cross, they showed not a trace of a frown, nor was there any frown when they were enraged. Twice I took two Chimpanzees from their rather dark room suddenly into bright sunshine, which would certainly have caused us to frown. They blinked and winked their eyes, but only once did I see a very slight frown. On another occasion I tickled the nose of a Chimpanzee with a straw, and, as it crumpled up its face, slight vertical furrows appeared between the eyebrows. I have never seen a frown on the forehead of the Orang. “A fresh-water Turtle was placed, at my request, in the same compartment in the Zoological Gardens with many Monkeys, and they showed unbounded astonishment, as well as some fear. This was displayed by their remaining motionless, staring intently with widely-opened eyes, their eyebrows being often moved up and down. Their faces seemed somewhat lengthened. They occasionally raised themselves on their hind legs to get a better view. They often retreated a few feet, and then, turning their heads over one shoulder, again stared intently. It was curious to observe how much less afraid they were of the Turtle than of a living Snake, which I had formerly placed in their compartment, for in the course of a few minutes some of the Monkeys ventured to approach and touch the Turtle. On the other hand some of the larger Baboons were greatly terrified, and grinned as if on the point of screaming out. When I showed a little dressed-up doll to the black Baboon, it stood motionless, stared intently with widely-opened eyes, and advanced its ears a little forwards; but when the Turtle was placed in its compartment, this Monkey also moved its lips in an odd, rapid, jabbering manner, which the keeper declared was meant to conciliate or please the Turtle. I was never able clearly to perceive that the eyebrows of astonished Monkeys were kept permanently raised, though they were frequently moved up and down. Attention, which precedes astonishment, is expressed by man by a slight raising of the eyebrows, and Dr. Duchenne informs me that when he gave to the Monkey formerly mentioned some quite new article of food, it elevated its eyebrows a little, thus assuming an appearance of close attention. It then took the food in its fingers, and with lowered or rectilinear eyebrows scratched, smelt, and examined it, an expression of reflection being thus exhibited. Sometimes it would throw back its head a little, and