fc4 THE HAIR. 



often induce horripilation, and if the eye is kept on an indi- 

 vidual hair at this time, it is seen to rise quickly as the skin 

 becomes rough, and to fall again as the horripilation subsides. 

 I have never seen more than one muscle to each hair-follicle 

 in the scalp; and in order that a single muscle may by its 

 contraction simply erect a hair, it must be placed in a plane 

 perpendicular to the surface of the skin and parallel to the 

 hair; this explains the fact before alluded to, that a section 

 made in such a plane is sure to contain the muscles in their 

 entire length, if at all, while sections in other planes cut 

 across either the muscles or the hairs." 



Mr Lister goes on to say, that " With regard to the state- 

 ment of Henle, that muscular tissue exists in parts destitute 

 of hairs, I have searched with diligence many good sections 

 of both the palm and the sole, without having been able to 

 discover any evidence of it on the exterior of either the 

 sudoriferous glands or blood-vessels of these parts. In a 

 section treated with acetic acid, the elongated nuclei of the 

 internal coat of a small blood-vessel sometimes give it an 

 appearance that might at first sight be mistaken for that of 

 unstriped muscle ; but this is an error easily avoided by care, 

 and I cannot but agree with Kolliker in thinking that, in 

 some way or other, his boiled preparations have led Henle 

 into error. 



" In order to verify Kolliker's statement that no unstriped 

 muscle exists in connexion with the vibrissse of mammalia, I 

 examined the feelers of a cat. These large hairs extend far 

 down into the tissues beneath the skin, and have a more com- 

 plex muscular apparatus than the small hairs of the human 

 skin. Bundles of muscles extend from the lower part of the 

 gigantic hair-follicle obliquely upwards to the inferior aspect 

 of the skin, and, in addition to these, there is muscle sur- 

 rounding the large nerve that enters the base of each hair- 



