=Cutaneous veins.=--The bend of the elbow in young children and in persons with fat and round arms, presents a semicircular fold of which the curve embraces the lower part of the biceps; but in muscular persons we see the distinct boundaries of the triangular space, formed by the pronator teres on the inner side, and the supinator longus on the outer. Here can be traced, standing out in strong relief under the thin white skin, the superficial veins, which, in days gone by, when bloodletting was the fashion, were of such great importance. Their arrangement, although subject to variety, is very much like the branches of the letter M, the middle of the M being at the middle of the elbow. Of these branches the median basilic, which runs over the tendon of the biceps, is the largest and most conspicuous, and is generally selected for venesection; it crosses the course of the brachial artery, nothing intervening but the semilunar aponeurosis from the tendon of the biceps. 137. =Landmarks of elbow.=--It is of great importance to be familiar with the relative positions of the various bony prominences about the elbow. We can always feel the internal and external condyles. The internal is the more prominent of the two, and a trifle higher. =Olecranon.=--We can always feel the olecranon. This is somewhat nearer to the inner than to the outer condyle. Between the olecranon and the internal condyle is a deep depression in which lies the ulnar nerve (vulgarly called the ‘funny bone’). On the outer side of the olecranon, just below the external condyle, is a pit in the skin, constant even in fat persons (when the elbow is extended). This pit is considered one of the beauties of the elbow in a graceful arm; it is seen in a child as a pretty little dimple. To the surgeon it is most interesting, as in this valley behind the supinator longus and the radial extensors of the wrist he can distinctly feel the head of the radius rolling in pronation and supination of the forearm. It is, therefore, one of the most important landmarks of the elbow, since it enables us to say whether the head of the radius is in its right place, and whether it rotates with the shaft. Can the tubercle of the radius be felt? Yes, but only on the back of the forearm in extreme pronation. Its projection is then distinctly perceptible just below the head of the bone. =Relations of olecranon and condyles.=--To examine the relative positions of the olecranon and condyles in the different motions of the elbow joint, place the thumb on one condyle, the tip of the middle finger on the other, and the tip of the forefinger on the olecranon. In extension, the highest point of the olecranon is never above the line of the condyles; indeed, it is just in this line. With the elbow at right angles the point of the olecranon is vertically below the line of the condyles. In extreme flexion the point of the olecranon lies in front of the line of the condyles.