Note g — BOOK IV. (continued 2)

From Malpighi’s curious Observations of the Hair, I shall note three Things. 1. Their Structure is fistulous, or tubular; which hath long been a Doubt among the curious. Fistulosum [esse Pilum] demonstrant lustratio pilarum à caudâ & collo Equorum, &c.——præcipuè setarum Apri, quæ patentiorem ex fistulis compositionem exhibent. Est autem dictus Apri pilus Cylindricum corpus quasi diaphanum——fistularum aggere conflatum, & speciem columnæ striatæ præ se fert. Componentes fistulæ in gyrum situatæ in apice patentiores redduntur; nam hians pilus in geminas dividitur partes, & componentes minimæ fistulæ——libersores redditæ manifestantur, ita ut enumerari possunt; has autem 20, & ultra numeravi.——Expositæ fistulæ——tubulosæ sunt, & frequentibus tunicis transversaliter situatis, veluti valvulis pollent. Et quoniam Spinæ, in Erinaceis præcipui, &c. nil aliud sunt, quam duri & rigidi pili, ideo, &c. And then he describes the Hedgehog’s Spines, in which those Tubes manifestly appear; together, with medullary Valves and Cells; not inelegant, which he hath figur’d in Tab. 16. at the End of his Works.

That which this sagacious, and not enough to be commended Observer, took notice of in the Structure of Hair, and its Parity to the Spines; I have my self observ’d in some Measure to be true, in the Hair of Cats, Rats, Mice, and divers other Animals; which look very prettily when view’d with a good Microscope. The Hair of a Mouse, (the most transparent of any I have view’d,) seems to be one single transparent Tube, with a Pith made up of a fibrous Substance, running in dark Lines; in some Hairs tranversly, in others spirally, as in Fig. 14, 15, 16, 17. These darker medullary Parts, or Lines, I have observ’d, are no other than small Fibres convolved round, and lying closer together than in other Parts of the Hair. They run from the Bottom, to the Top of the Hair; and I imagine, serve to the gentle Evacuation of some Humour out of the Body; perhaps the Hair serves as well for the insensible Perspiration of hairy Animals, as to fence against Cold and Wet. In Fig. 14, 16, is represented the Hair of a Mouse, as it appears through a small Magnifier; and in Fig. 15, 17, as it appears when view’d with a larger Magnifier.

Upon another Review, I imagine, That although in Fig. 14, 15, the dark Parts of the Pith seem to be transverse; that they, as well as in the two other Figures, run round in a screw-like Fashion.