| OCR Text |
Show 1885.] MYOLOGY OF THE WATER-OPOSSUM. 15 Psoas parvus.-Very large, arising from sides of bodies of last three dorsal and first two lumbar vertebrae by tendinous fibres, and fronts of next four vertebrae by fleshy fibres. It is inserted by a narrow tendon into ilio-pectineal line just outside marsupial bone. Iliacus.-Arises from iliac fossa. Inserted by muscular and tendinous fibres into lesser trochanter of femur and into surface of bone beneath it, its lower fibres being closely connected with tendon of psoas. Gracilis.-Arises from lower two thirds of pubic symphysis and from a small portion of its descending ramus. It is inserted into inner surface of tibia by strong fibres at its upper part, and by a fascia closely united to lower part of insertion of semitendinosus below this. Pectineus consists of two small flat slips united at their origin :- 1. Arises from outer angle of base of marsupial bone by a narrow tendon. 2. Arises from pubes between former slip and insertion of psoas parvus. They are inserted into upper half of linea aspera superficial to adductor brevis, a narrow space existing between their insertions. Adductor brevis.-Arises from a small portion of pubic symphysis, ascending ramus of pubes, and inner part of marsupial bone. It is inserted into middle lip of linea aspera for its upper half. Adductor magnus.-Extensive origin from lower part of pubic symphysis, rami of pubes and ischium, and ischial tuberosity under cover of gracilis, semimembranosus, and semitendinosus. Its fibres converge and are inserted into triangular surface at lower third of linea aspera. The muscle has the appearance of being enfolded on itself, the fibres from the symphysis pubis and upper part of ramus forming a thin strap-like band which crosses the other fibres obliquely. Adductor longus.-Arises from pubic symphysis between origins of adductors brevis and magnus. It is inserted into lower half of linea aspera and inner condyle. Quadratus femoris.-Arises from ischial tuberosity. Inserted tween greater and lesser trochanters of femur. Gastrocnemius internus.-Arises from posterior part of inner condyle of femur. Its tendon is grooved on its deep aspect and embraces tendon of gastrocnemius externus. It is inserted on outer side of posterior surface of os calcis. Gastrocnemius externus.-Much larger than preceding muscle. It arises from external condyle of femur, receiving a band of fibres which arises from the sesamoid bone, which articulates with the head of the fibula. It forms a thick belly, which is partially separable into two parts, and is inserted into os calcis on inner side of gastrocnemius internus. Plantaris.-Arises in close connection with gastrocnemius externus from sesamoid bone, passes under gastrocnemei, and is inserted into fascia on inner side of foot. Popliteus.-Arises by narrow tendon from external condyle of femur. Inserted iato posterior surface of tibia at its upper half. |
