Felted

Felted is a term variously applied to hairy material that is densely packed or tangled, forming felt or felt-like structures. Apart from fibres in felt manufactured by humans, the term "felted" may apply to the condition of hair such as in the pathological condition known as felted hair, the tangled threads of the tissue of certain fungi, matted fibres in animal connective tissue, or the felted coating of certain plants. To say that something is felted need not imply that there have been any processes of matting, condensing and pressing fibres such those used in artificial production of felt fabric from hair or fibres.

Zoology

Examples of felted animal tissues include classes of connective tissue such as the dermis which the classic Gray's Anatomy describes as: "felted connective tissue, with a varying amount of elastic fibers and numerous bloodvessels, lymphatics, and nerves." Also, in describing the external coat or tunica adventitia of an artery: "consists mainly of fine and closely felted bundles of white connective tissue..." In such classes of connective tissue, felted structure is very important; it is versatile in resisting tearing and imparts strength together with shock absorption and elasticity in two or three dimensions at once, irrespective of the shape of the tissue.

Australian bug female on her fibrous waxy protection for the eggs.

Cochineal females. Note that the white waxy fibre does not cover the insect, but rather the eggs.

Phyllaphis fagi, Eriosomatinae, woolly beech aphid on a leaf.

Other examples of felted material in animal structures include fibrous structures coating the integument of some insects. Usually such a felted coating is not living tissue, but consists of waxy fibres and is not particularly strong, but serves as protection from either excessive desiccation or moisture. It is particularly common in some families of the Hemiptera. In some species it occurs only as an outer coat of the immature insect, but in others, such as many of the Coccoidea, including the "Australian bug", Icerya purchasi and cochineal, Dactylopius species, it is secreted throughout the life of the insect and serves largely to protect the eggs rather than the insect. In other species, such as many of the "woolly aphids", the Eriosomatinae, the most spectacular fluff is borne on the adult insect itself.