The sheep : its external structure & internal organs / by A. Seyfferth ; revised and edited by G.T. Brown.

  • Seyfferth, A.
Date:
[1896?]
Catalogue details

Licence: Public Domain Mark

Credit: The sheep : its external structure & internal organs / by A. Seyfferth ; revised and edited by G.T. Brown. Source: Wellcome Collection.

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    THE SHEEP. The Sheep (Ovis, L.) belongs to the division Vertebrata, class Mammalia, order Euminantia, and family of the Cloven-footed Mammalians. They are elegant, agile animals, with a covering of wool. They have slender bodies, head narrowing very much towards the front, and fairly large eyes and ears. In the horned breeds, the horns are angular trilateral, with protuberances running obliquely; have a side direction, are spirally shaped and twisted, and rest on a bony protuberance, which has the same direction as the horn, but is much shorter than this latter. As a rule horned sheep only possess one pair of horns, though there are some with four or even more horns ; these, however, must be considered as accidental formations only. Hornless sheep have thus on each side either small osseous bosses, or shallow hollows on the frontal bones, as indications of the horn-roots (or lumps). Hornless rams occasionally exhibit on the suture of the head a short core of horn, which is provided on the outside with laminae of horn. Sheep possess the so-called lachrymal pits, which lie in front of the anterior edge of the orbit, towards the inner corner of the eye. The outer skin forms a depression (lachrymal furrow) over the lachry- mal pit; but this, however, has nothing to do with the lachrymal secretion. The closely-allied goats, as well as several kinds of wild sheep, lack the lachrymal pits, and therefore the furrow likewise. The upper lip is cleft and covered with delicate hairs. The nose is rather long. The ears generally stand apart, but occasionally they hang down; short ears are also carried directed upwards. The sheep has 24 molars in the upper and lower jaw, and 8 incisors, which latter are in the lower jaw only. Instead of incisors, the upper jaw has a fibrous pad. The body of the sheep is covered with hair and wool. The hair is either a short—generally reddish or greyish brown, partly whitish— surface hair, or the body is furnished with bristles, mingled with downy hair; or it has woolly hair, while the face and legs are covered with downy and surface hairs. In this last particular the Merino sheep forms an exception, its face and feet being for the most part thickly covered with wool. Bristly hairs, downy hairs, and woolly hairs are generally of a white colour; but there are also grey, brown, and black hairs of this kind. The changing of the coat occurs regularly in wild sheep, and irregularly in the domestic animals. As in the consideration of the various breeds the character of the hairy coat, and of the wool of the sheep, must often be mentioned, a short description may be given. The hair consists of three layers—the cortical substance, medullary matter, and the cuticle. The first-named forms the chief part of the hair; it is the middle layer enclosing the medullary matter, while the