The femoral artery can be used all the way from where it leaves the body at Poupart's ligament until it reaches Hunter's canal. At Poupart's ligament the artery is very superficial, being covered only by the skin, superficial fascia and superficial lymphatic glands, but it gets deeper further down, being covered not only by the above named tissues, but also by muscles, making it very difficult to raise in the middle and lower thirds of the thigh. About five to seven inches below Poupart's ligament the artery passes under the adductor magnus muscle, and enters what is known as Hunter's canal. Because this artery does get deeper as it courses down the thigh, it is generally raised in the upper third. A knowledge of the anatomy of the vessels of the thigh and leg will be of value in treating accidents when this member is injured. _Scarpa's triangle_ is a triangular space, the apex of which is directed downward, and the sides formed externally by the sartorius muscle, internally by the inner border of the adductor longus muscle, and above by Poupart's ligament. The floor of the space is formed from without inward by the ilio-psoas pectineus and the adductor longus muscles. The space is divided into two nearly equal divisions by the femoral vessels, which extend from the middle of its base to its apex, the artery giving off in this situation the superficial and profunda branches, and the vein receiving the deep femoral and the internal saphenous veins. Besides the vessels and nerves this space contains some fat and lymphatics. _Hunter's canal_ is the aponeurotic space in the middle third of the thigh, extending from the apex of Scarpa's triangle to the femoral opening in the adductor magnus muscle. Hunter's canal contains the femoral artery and vein inclosed in their own sheath of areolar tissue, the vein being behind and on the outer side of the artery, and the long saphenous nerve lying at first on the outer side and then in front of the vessels. _Linear Guide._—The guide for the femoral artery is represented by a line drawn from the center of Poupart's ligament to the inner side of the knee joint. Poupart's ligament extends from the crest of the ileum bone to the top of the pubic bone. To determine the center of Poupart's ligament for the right leg, get on the right side of the body and with the left hand, place the second finger on the top of the pubic bone and the thumb on the crest of the ileum bone, then let the index finger drop down between the two which will represent the commencement of the femoral artery. _Anatomical Guide._—The artery runs through the center of Scarpa's triangle from the center of its base to its apex. In the middle third of the thigh the artery passes beneath the vastus medialis muscle and enters Hunter's canal.