Conservation and restoration of fur objects made from keratin, which is also the protein that makes up skin, feathers, nails, hooves, claws, and horns. "The way I think a lot of people understand fur versus hair is in the density of follicles," says Ross McPhee, Curator of the Department of Mammalogy at the American Museum of Natural History. "So for fur-bearing animals—which were converted into coats and so-forth—people always wanted it to be something that was very dense, so there’s the idea therefore that fur is dense, and it certainly is in [the] kinds of fur-bearers that we use for this purpose. Whereas hair is not
Development of the nervous system in humans matter). Nerve fibers emerge from these neuroblasts to form the marginal layer (the white matter). The ventral part of the mantle layer (the basal plates) forms the motor areas of the spinal cord, whilst the dorsal part (the alar plates) forms the sensory areas. Between the basal and alar plates is an intermediate layer that contains neurons of the autonomic nervous system. Late in the fourth week, the superior part of the neural tube flexes at the level of the future midbrain—the mesencephalon. Above the mesencephalon is the prosencephalon (future forebrain) and beneath it is the rhombencephalon (future hindbrain). The