In the dog, the anterior portion of the gluteus maximus arises from the sacrum, while some fibres situated further forward arise from the surface of the gluteus medius, near the iliac spine, and from the tensor of the fascia lata with which these fibres are blended. The posterior portion, united to the preceding--that is to say, to those of its fibres which arise from the sacrum--takes its origin from the first coccygeal vertebra. These two portions are directed towards the femur, to be inserted into the great trochanter, and to the external branch of the superior bifurcation of the linea aspera. In the cat, the posterior bundle is less definitely blended with the anterior. By a long and slender tendon which, behind, turns around the great trochanter, and passes along the surface of the fascia lata, it proceeds to join the knee-cap. In the pig, the posterior portion is much more developed. In the horse, the anterior portion arises from the internal iliac spine (posterior in man), from the external iliac spine (anterior in man), and, between these two osseous points, from the aponeurosis, which covers the gluteus medius. Between these two origins the muscle is deeply grooved, so that the tendency is to divide into two portions, each of which is directed towards one of the iliac angles. In this groove the gluteus medius is to be seen. The fleshy bundles converge, and are directed towards the external aspect of the femur, to be inserted into the osseous prominence known as the third trochanter, after passing beneath the fleshy fibres of the posterior portion. The latter, which is more considerable than the preceding portion, arises above from the sacral crest, from the aponeurosis which envelops the coccygeal muscles, from the sacro-sciatic ligament, and from the tuberosity of the ischium. From this origin it passes downwards, expands, then, describing a curve with the convexity behind, it becomes narrowed, and proceeds to be inserted by a deep fasciculus into the third trochanter, to the fascia lata, and, lastly, to the knee-cap by the inferior part of its tendon. Above, its posterior border is covered by the semi-tendinosus; interiorly, the same border is in relation with the biceps femoris. In the ox, the two parts of the great gluteal muscle are blended together.