STRUCTURE OF HAIRS. 



705 



guished by the projections on their surface, which are formed by 

 extensions of the component scales of the Cortical substance ; these 



Fig. 364. 



Fig. 365. 



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Fig. 364. Hair of Sable, showing large rounded cells in its 

 interior, covered by imbricated scales or flattened cells. 



Fig. 365. Hair of Musk-deer, consisting almost entirely of poly- 

 gonal cells. 



are particularly well seen in the hairs of one of the Indian species, 

 which has a set of whorls of long narrow leaflets (so to speak) 

 arranged at regular 



intervals on its stem p IG> 3gg 



(c). In the Hair of A ^ r 



the Pecari (Fig. 

 367), the Cortical 

 envelope sends in- 

 wards a set of radial 

 prolongations, the 

 interspaces of which 

 are occupied by the 

 polygonal cells of the 

 Medullary substance ; 

 and this, on a larger 

 scale, is the struc- 

 ture of the ' quills ' 

 of the Porcupine; 

 the radiating parti- 

 tions of which, when 

 seen through the 

 more transparent 

 parts of the Cortical 

 sheath, give to the 

 surface of the latter 

 a fluted appearance. 

 The Hair of the 



a, Small Hair of Squirrel : — B, Large Hair of 

 Squirrel : — c, Hair of Indian Bat. 



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