RUDIMENTS. 19 



to that of man. It is evident that the folding over of the 

 tip of such an ear, unless it changed greatly during its 

 further development, would give rise to a point projecting 

 inward. On the whole, it still seems to me probable that 

 the points in question are in some cases, both in man and 

 apes, vestiges of a former condition. 



The nictitating membrane, or third eyelid, with its ac- 

 cessory muscles and other structures, is especially well 

 developed in birds, and is of much functional importance 

 to them, as it can be rapidly drawn across the whole eye- 

 ball. It is found in some reptiles and amphibians, and in 

 certain fishes, as in sharks. It is fairly well developed in 

 the two lower divisions of the mammalian series, namely, 

 in the monotremata and marsupials, and in some few of 

 the higher mammals, as in the walrus. But in man, the 

 quadrumana, and most other mammals, it exists, as is ad- 

 mitted by all anatomists, as a mere rudiment, called the 

 semilunar fold.* 



The sense of smell is of the highest importance to the 

 greater number of mammals to some, as the ruminants, in 

 warning them of danger; to others, as the carnivora, in 

 finding their prey; to others, again, as the wild boar, for 

 both purposes combined. But the sense of smell is of 

 extremely slight service, if any, even to the dark colored 

 races of men, in whom it is much more highly developed 

 than in the white and civilized races, f Nevertheless it 

 does not warn them of danger, nor guide them to their 



*Muller's "Elements of Physiology," Eng. translat., 1842, vol. ii, 

 p. 1117. Owen, "Anatomy of Vertebrates," vol. iii, p. 260; ibid, on 

 the Walrus, "Proc. Zoolog. Soc.," November 8, 1854. See also R. 

 Knox, "Great Artists and Anatomists," p. 106. This rudiment ap- 

 parently is somewhat larger in Negroes and Australians than in Euro- 

 peans, see Carl Vogt, " Lectures on Man," Eng. translat., p. 129. 



f 'The account given by Humboldt of the power of smell possessed 

 by the natives of South America is well known, and has been con- 

 firmed by others. M. Houzeau (" Etudes sur les Facultes Mentales," 

 etc., torn, i, 1872, p. 91) asserts that he repeatedly made experiments, 

 and proved that Negroes and Indians could recognize persons in the 

 dark by their odor. Dr. W. Ogle has made some curious observa* 

 tions on the connection between the power of smell and the coloring 

 matter of the mucous membrane of the olfactory region, as well as of 

 the skin of the body. I have, therefore, spoken in the text of the 

 dark colored races having a finer sense of smell than the white races. 

 See his paper, "Medico-Chirurgical Transactions," London, vol. liii, 

 1870, p. 276. 



