My Dear Sir

Undoubtedly the great muscle of the scalp should be regarded as a skin muscle and it is through this same muscle that the eyebrows are elevated, their depression being affected by another muscle called corrugator supercilii—¹ Those muscles which move the ear as a whole evidently belong to the same group, and the muscles of the alæ of the nose, of the lips & the sphincter muscles of the mouth and anus are apparently also of the same character—² Many of these from their position are evidently for the purpose of moving not only the skin, but those appendages (hairs in the human body) which are somewhat numerous in those localities.³ There is one spot in the human body however, viz: the skin of the inner side of the palm of the hand to which a fairly marked panniculus is attached. The muscle is called palmaris brevis. But one cannot say that its use is primarily for the movement of hairs as the inner side of the palm is destitute of those appendages—

Bye the way the power not only of moving the scalp but the ears to & fro, is possessed by some persons— I have seen it more than once—⁴

In connection with the movements of the hairs, not only in the scalp but elsewhere, I may remind you that the individual hairs have special muscles attached to them, which are attached on the one hand to the corium immediately beneath the epidermis & on the other to the outer surface of the hair follicle— These muscles by their contraction project the individual hairs & produce the condition known as goose skin (cutis anserina), such as we experience on sudden application of cold to the surface. These muscles are of the non striped or involuntary form— They were first discovered by Kölliker & have been carefully described by Lister in Vol VI of Microscopical Journal— The panniculus carnosus of man & quadrupeds is on the other hand formed of striped or voluntary fibre—⁵

Hence it would appear that the movement of the skin & of its appendages en masse is effected by the agency of a more or less generally distributed voluntary muscle, whilst the movement of individual hairs is effected by a special involuntary muscle attached to each hair follicle.

I remain | very truly yrs | W^m Turner

N.B. In the skin of the hedge hog there is no difficulty in seeing that the ‘quills’ are moved by the voluntary panniculus. A special reason (defensive purposes) requiring that they should be under the influence of the will—⁶

Kölliker states that in the cat & other mammals the vibrissæ are moved by striped, i.e. voluntary, & not involuntary fibres—⁷