_Fig._ 6. The fluke-worm; _a._ the mouth; _b._ the reproductive apparatus; _c._ _c._ vessels for the distribution of the blood. PLATE II. _Fig._ 1. Dorsetshire Ram. _Fig._ 2. South Down Ram. The figures in this plate are borrowed from the beautiful cuts in the work on _Sheep_, published by the Society for the Diffusion of Useful Knowledge. PLATE III. _Fig._ 1. New Leicester Ram. _Fig._ 2. Cheviot Ram. The portrait of a very superior animal, in the possession of my friend Mr Laurie of Terregles town. Premiums were awarded to Mr Laurie for both of these sheep at the last meeting of the Highland Society in Dumfries. _Fig._ 3. View of the veins of the face and neck; _f.v._ facial vein; _j.v._ jugular vein. PLATE IV. _Fig._ 1. Black-faced Ram. _Fig._ 2. Merino Ram. PLATE V. _Figs._ 1. 2. 3. from the _Quarterly Journal of Agriculture_, represent the most approved mode of washing and shearing sheep. _Fig._ 4. Tubular structure of hair and wool. _Fig._ 5. Relative positions of the layers of the skin, mode in which the hairs rise from, and situation of, the sebaceous follicles; _a._ the cuticle; _b._ the mucous layer; _c._ the true skin; _d._ sebaceous follicles; _e._ hairs rising from the true skin; _f._ the yolk. PLATE VI. _Fig._ 1. Section of the lung of a sheep which has been over-driven. _Fig._ 2. Section of the lung of a sheep which has been affected with Rot. PLATE VII. _Fig._ 1. The _Cysticercus tenuicollis_. _Fig._ 1. _a._ Head of the same magnified. _Fig._ 2. The _Coenurus Cerebralis_. _Fig._ 2. _a._ Heads of the _Coenurus_ magnified. _Fig._ 3. The _pentastoma_. Hitherto supposed to exist only in the dog and wolf, but discovered recently in the frontal sinus of the sheep by my friend Mr Rhind of Edinburgh, by whom the drawing for this figure was kindly furnished. PLATE VIII. _Fig._ 1. Hydatid in the brain of a sheep (from a drawing by my friend Dr Kirk of Deal); _a._ the right lobe of the cerebellum or lesser brain distended with fluid, inclosed in a membraneous bag, as shown at _b._, where an incision has been made to expose it; and at _c._ where it is shining through the _pia mater_, one of the coverings of the brain. _Fig._ 2. Showing the extent to which hydatids sometimes distend the ventricles of the brain; _a._ the dilated ventricle of the left side; _b._ _b._ convolutions passing from back to front; _c._ _d._ depth of the furrows. THE SHEEP. CHAPTER I. HISTORY OF THE SHEEP. (1.) _Origin of the Sheep._--As the origin of our domesticated animals has afforded scope for much curious speculation, so none have attracted a greater degree of attention in this respect than the sheep. Into these arguments, however, it would be absurd to enter; I shall therefore content myself with such opinions as are deemed the best.