56 HAIR. [INTROD. 



As to the partial nakedness of the skin of many animals 

 (Man, &c.), several suggestions have been made. It has been 

 variously supposed that the covering of hair has been gradually 

 lost by Man, in correlation with the use of clothes ; with the heat 

 of the sun ; for ornamental purposes under sexual selection x ; or 

 perhaps as a protection from parasites' 2 . Various suggestions 

 have also been made to explain the persistence of hair at the 

 junction of the limbs and on the head and face. To a con- 

 sideration of the origin of nakedness, the evidence of Variation in 

 some measure contributes, and though the bearing is not very 

 direct, it may illustrate the futility of inquiries of this kind made 

 without regard to the facts of Variation. 



Mouse (Mus musculus) : male and pregnant female found in a 

 straw-rick at Taplow ; both were entirely naked, being without hairs 

 at all, excepting only a few dark-coloured whiskers. The skin was 

 thrown up into numerous prominent folds, transversely traversing the 

 body in an undulating manner. This condition of the skin obtained 

 for them the name of " Rhinoceros mice." The ears were dark or 

 blackish, the tail ash-coloured, and the eyes black, indicating that they 

 were not albinos. The exfoliations from the skin were examined 

 microscopically but no trace of hair-follicles was found, nor any 

 suggestion of disease. The animals were active and healthy. 



The young ones, when born, were similar to the parents. The 

 teeth were normal. 



In the Museum of the College of Surgeons is a precisely similar 

 specimen which was found in a house in London. Gaskoin, Proc. 

 Zool. Soc, 1856, p. 38, Plate. 



Three specimens of the common Mouse (Mus musculus) were caught 

 in the town of Elgin. The whole bodies of these three creatures "were 

 completely naked — as destitute of hair and as fair and smooth as a 

 child's cheek. There was nothing peculiar about the snout, whiskers, 

 ears, lower half of the legs and tail, all of which had hair of the usual 

 length and colour. They had eyes as bright and dark as in the common 



variety At least two others were killed in the same house where 



these were found." Gordon, G., Zoologist, 1850, vm. p. 2763. 



Shrew. (Sorex sp.) "whole of upper surface of head and body 

 destitute of hair, and skin corrugated like that of Naked Mice figured 

 in P. Z. S., 1856 ;" sent to Brit. Mus. by Mr P. Garner. Gray, J. E., 

 Ann. and Mag. of N. B., 1869, S. 4, iv. p. 360. 



In connexion with these cases, the following fact is interesting : 

 Heterocephalus is a genus of burrowing rodent from S. Africa. It contains two 

 species, of which one is about the size of a mouse and the other is rather larger. 

 They are characterized by possessing an apparently hairless skin which is on the 

 head and body of a wrinkled and warty nature. On closer inspection the skin is 

 seen to be furnished with fine scattered hairs, but there is no general appearance of 

 a hairy covering. There is no external ear in these animals. Oldfield Thomas, 

 P. Z. S., 1885, p. 845, Plate LIV. 



Naked horses have often been exhibited. Such a horse causht in a 



&* 



1 C. Darwin, Descent of Man, i. p. 142. 



2 Belt, Naturalist in Nicaragua; see also Hudson, Naturalist in La Plata, 1892. 



