574 DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 
Adductor longus primus. If this is really a separate muscle from what is termed the 
adductor longus secundus, it is only divisible on account of the rather different place 
of insertion from the latter. It arises by a broad, short, thin, flattened tendon from 
the outer side of the brim of the pelvis, close to the crest and spinous process (Ad./’, 
figs. 36 & 35). Proceeding outwards and upwards, the muscle is inserted into the 
middle of the shaft of the femur for the breadth of an inch along the linea aspera. 
The deep vessels of the thigh wind round the lower bodies of the insertion as they 
dip between the fibres of the adductor magnus. 
Adductor longus secundus. A larger muscle (Ad./*), lying on the same plane as the 
preceding, the fibres being deeply compressed as they cross from the pelvis to the thigh. 
They arise from around the obturator foramem and on the bone between that and the 
symphysial crest, deeper, however, than the last muscle. The muscular insertion 
extends from the great trochanter to the middle of the femur, covering all the bone 
behind. The adductor longus secundus is in relation with the small adductores, the 
great adductores, deeply with the obturator externus, quadratus femoris, and the extra 
slip of the gluteus maximus. 
Action. The two magni bring the femur and tibia towards the pelvis. The adductor 
longus primus is an adductor and rotator inwards of the thigh. The adductor longus 
secundus is an adductor and rotator outwards, the latter because the insertion is far 
behind. 
Adductor brevis primus. A short, fleshy muscle arising from the outer side of the 
pectineal eminence, anterior to but beneath the pectineus muscle (Ad.b'). The adductor 
brevis primus rolls fleshy round the hip-joint, and is inserted into the femur, below 
the neck and trochanteric fossa. 
Adductor brevis secundus (Ad.0’). Arises posterior to the pectineal eminence and 
muscle, and closely adjoining the obturator externus. The direction of the fibres is at 
a slight angle to those of the primus; and they are inserted fleshy into the back of the 
femur, between the linea aspera and the trochanter. 
Use. These two adductors of the thigh rotate outwards the head of the femur. 
Semitendinosus—A muscle which I take to be the semitendinosus, because of its 
insertion corresponding to what is ordinarily regarded as such, arises as a broad strip 
from the outer border of the ischium, and, passing almost straight across to the tibia as 
a muscular band, is inserted by membrane into the middle of that bone (S¢, fig. 33). 
The relations of the semitendinosus are :—at its origin, the adductor magnus primus; 
behind or deeply, the ischiatic nerves and arteries and enlarged lymphatic gland; the 
gastrocnemius and popliteus; whilst it lies across the sacro-peronewus muscle, which is 
posterior to it, but in close relation at its insertion, Lastly, the great broad gracilis lies 
over and hides the semitendinosus when the parts are undisturbed. This is an adductor 
of the lower leg towards the pelvis, and consequently rotator inwards. 
Semimembranosus.—It is a great, flat, thinnish, fleshy expanse (Sm, figs. 33, 34, & 36), 
