HAIR AND UNDER-FUR 



cular arrangement of the individual hairs among mammals ; 

 they are not hj any manner of means vScattered without order, 

 but show a definite and regular arrangement, which varies with 

 the animal. For instance, in an American Monkey {Midas), the 

 hairs arise in threes — tliree hairs of ecjual size s])ringingfrom the 

 epidermis close together ; in the Paca (Coelut/rn/fs) there are in 

 each group three stout hairs alternating with three slender hairs. 

 In some forms a number of hairs spring from a common point : 

 in the Jerboa {Dvpus) twelve or thirteen arise from a single hole ; 

 in Ursiis arrfns there is the same general plan, but there is one 

 stout hair and four or five slender ones. There are numerous 

 other complications and modifications, but the facts, although 

 interesting, do not appear to throw aiiy light upon the mutmd 

 affinities of the animals. Allied forms may have a very different 

 arrangement, while in forms which have no near relatiojiship the 

 plan may lie very similar, as is shown l)y tbe examples cited from 

 T)r. Meijerle's paper. The groups of hairs, moreover, have them- 

 selves a definite placing, which the same anatomist has compared 

 with the disposition of the l)undles of hairs behind and l^etween 

 the scales of the Armadillo, and which has led him to the view 

 that the ancestors of mammals were scaly creatures — a view also 

 supported by Professor Max Weber,^ and not in itself unreason- 

 able when we consider the numerous points of affinity l)etween 

 the primitive Mammalia, and certain extinct forms of reptiles."' 



The hairs are greatly modified in form in different mannnals 

 and in different paits of their l)odies. It is very connnonly the 

 case that a soft under-fur can be distinguished from the longer and 

 coarser hairs, which to some extent hide the latter. Thus the 

 " sealskin " of commerce is the under-fur of the Ofaria vrsina of 

 the North. The coarser hairs may l)e further differentiated into 

 lu'istles ; these again into spines, such as those of the Hedgehog 

 and of the Porcupine. Again, the flattening and agglutination 

 of hairs seems to be responsible for the scales of the Manis 



^ " Bemeikungen liber den Ursianing der Haare," Anat. An~. 1893, p. 413. 



- See for this matter, p. 90. Dr. Bonavia has recently advanced {Studies in 

 Evolution., London, 1895) the somewhat fantastic view that the pigment-patches 

 of Carnivorons and other mammals are a renuniseence of an earlier scaly condition. 

 There is no direct evidence that the primitive mammals were scaly, nor are the 

 Monotremata or Marsupials furnished with any more traces of such a con- 

 dition than are other mammals : and tliey are the most lowly organised of existing 

 .Mammalia. 



