A person fond of observing cannot fail to have arrived at the conclusion that a man’s daily calling moulds his features. Place a soldier, a sailor, a compositor, and a clergyman side by side, and who will not immediately detect a marked difference in their physiognomies? The muscles of the features are generally described as arising from the bony fabric of the face, and as inserted into the nose, the corners of the mouth, and the lips. But this description gives a very inadequate idea of their true insertion. They drop fibres into the skin all along their course, so that there is hardly a point of the face which has not its little fibre to move it. The habitual recurrence of good or evil thoughts, the indulgence in particular modes of life, call into play corresponding sets of muscles which, by producing folds and wrinkles, give a permanent cast to the features, and speak a language which all can understand, and which rarely misleads. Schiller puts this well when he says that ‘it is an admirable proof of infinite wisdom that what is noble and benevolent beautifies the human countenance; what is base and hateful imprints upon it a revolting expression.’ _THE NECK._ 23. =Subcutaneous veins.=--Notice first the direction of the subcutaneous veins. The chief subcutaneous vein is the external jugular. Its course corresponds with a line drawn from the angle of the jaw to the middle of the clavicle, where it joins the subclavian. It is made more prominent by putting the sterno-mastoid into action, or by gentle pressure on the lower end of the vein. It is exceptionally joined by a branch which runs over the clavicle, and is termed ‘jugulo-cephalic.’ The anterior jugular generally runs along the front border of the sterno-mastoid. 24. =Parts in central line. Os-hyoides.=--Immediately below and nearly on a level with the lower jaw we feel the body of the os-hyoides, and can trace backwards on each side the whole length of the cornua. They might easily be broken by the grasp of a garotter. Below the body of the os-hyoides is the gap above the thyroid cartilage. This gap corresponds with the anterior thyro-hyoid ligament and the apex of the epiglottis; so that in cases of cut throat in this situation, nearly the whole of the epiglottis lies above the wound. =Thyroid cartilage.=--The projection and depth of the notch in the thyroid cartilage, or ‘pomum Adami,’ varies in different persons. Between the notch and the hyoid bone there is a large bursa, which facilitates the play of the cartilage beneath the bone in deglutition. The notch does not appear till puberty, and is throughout life much less distinct in the female than the male. The finger can trace the upper borders and cornua of the thyroid cartilage: its lower cornua can be felt by the side of the cricoid.