48 TKICHOLOGIA MAMMALIUJI; 



let him pick one of these with a needle, and the end of a hair (the body of which lies 

 under the epidermis) will obtrude. With a pair of tweezers, this new hair maybe drawn 

 out to a considerable length. In a section of the skin these young hairs may be detected, 

 partly coiled, the apices seeking their way, as it were, through the epidermis, by one of 

 these pores. But all this is entirely at variance with the notion that the follicle is formed 

 by an inward turning of the cutis and is lined by a reflection of the epidermis. 



Of Pile without a Follicle. But it can be demonstrated that the idea of the follicle being 

 formed by the turning inwardly of 1he dermis is chimerical : 1st. By the hair of the head 

 of the foetus. We have, in our cabinet, a foetus of three months, upon whose head is no 

 hair; we have another of five months, upon whose head there are hairs, but none of them 

 have either button or follicle.* (See fig. 52 a.) We have a third specimen of hairs from 

 a full-grown foetus, which was taken, dead, from the body of a female obtained for dis- 

 section. Upon these hairs, also, there are no traces of either button or follicle. (See 

 fig. 52 b.) 



These are specimens of imperfect hairs, and seem to prove that pile does not "take its 

 origin in a follicle." We also call attention to fig. 53 c, which represents a curious con- 

 nection of three hairs of the horse " Diligence," viz : one mane hair that has come to 

 maturity, and two smnllerones, one of which appears to be an imperfect hair, probably 

 never having had a button or follicle. 



But the suit of skin-specimens, above referred to, explains this subject completely, and 

 puts this matter entirely at rest. In ihe various sections we have made of these, the yoiing 

 hairs that have not yet pierced the epidermis may be traced through every stage, from the 

 cells to their development. 



First is discovered, in the dermis, a collection of dark-colored dots, granules, or cyto- 

 blasts, the precursors and origin of the forthcoming hair. (See fig. 53 "a,") 



Secondly, (immediately alongside,) is another collection of granules, partly enclosed in 

 the faint outlines of a forming hair. Here we see some of the granules passing gradually 

 into lines or fibres. (See fig. 53 " b.") No button or follicle is yet to be seen. 



Thirdly, fig. 53 c shows the button just forming ; the inferior extremity of it a faint 

 outline, while the granules have ascended and condensed in the superior portion of the 

 button and the inferior extremity of the shaft; but no follicle yet appears. 



Fourthly, fig. 53 d represents a button formed, except that the lower extremity is not 

 yet closed ; but no follicle is yet seen. 



* Examination and Description of ihe hair of the head of a five months fetus, of one of the oval-haired species. Specimen 

 presented by Dr. Joseph Leidy, llth of April, 1850. Length, about 2 millimeters; shape, oval; diameter, 2 O f a milli- 

 meter; color, very light, translucent; not much lustre; direction, flowing; inclination, at an acute angle to the epidermis ; 

 button, sheath and follicle, none. The shaft terminates in the dermis in a slight swelling, which exceeds, by J, the diameter 

 of the shaft; truncated at the posterior extremity, and around which arc assembled dark-colored dots or grains, in groups 

 of various shapes and sizes, but generally extending laterally from the end of the shaft, and rarely measuring more than 

 -i of a millimeter. Shaft cortex, squamose, more than 200 scales upon the length of a millimeter. Intermediate 

 fibres, minute; one measured the ^1^ of a millimeter. Centre no central canal; the coloring matter disseminated 

 throughout the shaft in lines too minute for measurement. Apex generally pointed, but occasionally abrupt; none fur- 

 cated; diameter of the point, the T7 'o7r of a 



