As with plants so with animals, we find good reason for inferring that while the specialities of the Tegumentary parts must be ascribed to the natural selection of favourable variations, their most general traits are due to the direct action of surrounding agencies.
"Essays: Scientific, Political, & Speculative, Vol. I"
Herbert Spencer
The Tegumentary envelope of the head, as well as the dura-matral lining, serves to damp cranial vibration consequent upon concussion; while the sutural isolation of the several component bones of the cranium also prevents, in some degree, the extension of fractures and the vibrations of concussion.
"Surgical Anatomy"
Joseph Maclise