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Charles R. Bardeen 30 
third of the distance from the anterior extremity of the muscle, may 
be followed for a considerable distance toward the distal extremity of 
the muscle; the main trunk of the latter, which enters more anteriorly, 
extends a less distance distally and has a recurrent branch which ex- 
tends toward the proximal extremity of the muscle. This branch has 
been followed to the iliac insertion of the muscle and has been reported 
as extending to the M tensor fascie late. This last condition I have 
never seen. 
Vastus Lateralis——This muscle is differentiated from the quadriceps 
muscle mass by the development of septa between it and the vastus inter- 
medius. The muscle is usually composed of two distinct layers. an outer 
and an inner, separated by fascia containing nerves and blood vessels. 
Often the inner layer is further partially subdivided into two sheets by 
fascia in which nerves and blood vessels run. Commonly the nerve to the 
vastus lateralis divides into three branches of which one runs on the 
inner surface of the outer layer of the muscle, the second betwen the 
two sheets of the inner layer, and the third passes through the inner 
sheet of the inner layer to be distributed to the most lateral part of the 
vastus intermedius muscle. The larger intrinsic nerve trunks cross the 
fasciculi of the muscle sheets and about midway between the extremities 
of the fasciculi. 
Vastus Intermedius.—This is differentiated from the quadriceps 
muscle mass at the time of the ingrowth of the main nerves and blood 
vessels of the muscle. The muscle is composed of muscle lamelle con- 
centrically arranged about the diaphysis of the femur. The lowest, most 
distal, and most completely separated of these lamellw is the subcrureus 
muscle. Several nerves are distributed to the muscle. To the lateral 
region a branch from the nerve to the vastus lateralis usually extends. 
A special ramus from the femoral nerve generally passes to the middle 
portion, and from the nerve to the vastus medialis several branches are 
often given to the medial side of the muscle. 
Vastus Medialis—This muscle is differentiated from the quadriceps 
muscle mass by the formation of a connective tissue sheet between it and 
the vastus intermedius. Its nerve of supply runs along on the medial 
surface of the muscle sending branches from time to time into its sub- 
stance and finally near Hunter’s canal the terminal twigs of the nerve 
enter the muscle. The nerve is often more or less bound up with the 
saphenous nerve. The rami which enter the muscle extend at first across 
the fibre-bundles of the muscle sheet about midway between the extremi- 
ties of the fibre-bundles. 
