138 CHARLES DARWIN 



occur in many aberrant human individuals. Some 

 people possess the power of moving their scalps and 

 wagging their ears like dogs and monkeys ; others can 

 twitch the skin of their bodies, as horses do when 

 worried by flies. Mr. Woolner, the sculptor, pointed 

 out to Darwin a certain little projecting point or knob 

 on the margin of the ear, observed by him in the course 

 of modelling, which comparison shows to be the last 

 folded remnant or rudiment of the once erect and 

 pointed monkey-like ear-tip. The nictitating membrane, 

 or third eyelid, once more, which in birds can be drawn 

 so rapidly across the ball of the eye, and which gives 

 the familiar glazed or murky appearance, is fairly well 

 developed in the ornithorhynchus and the kangaroo, as 

 well as in a few higher mammals, like the walrus ; but 

 in man, as in the monkey group, it survives only under 

 the degenerate form of a practically useless rudiment, 

 the semilunar fold. Man differs from the other 

 Primates in his apparently hairless condition ; but the 

 hair, though short and downy, still remains on close 

 inspection, and in some races, such as the Ainos of 

 Japan, forms a shaggy coat like an orang's or a gibbon's. 

 A few long rough hairs sometimes project from the short 

 smooth down of the eyebrows ; and these peculiar bristles, 

 occasional only in the human species, are habitual in 

 the chimpanzee and in many baboons. Internal organs 

 show similar rudiments, of less enthralling interest, it 

 must be candidly confessed, to the unscientific outside 

 intelligence. Even the bony skeleton contributes its 

 share of confirmatory evidence ; for in the lower monkeys 

 and in many other mammals a certain main trunk nerve 

 passes through a special perforation in the shoulder- 



