316 DR. GADOW ON THE ANATOMY OF PTEROCLES. [ Mar. 21, 
from the posterior part of the crural plexus passes out, and then 
runs along the inner side of the thigh, superficially to the inner side 
of the proximal end of the leg (Ruge’s branch, as termed by me in 
my paper on the Ratitz). The ambiens muscle, on account of its 
nervous supply, belongs to the crural plexus, as the nerve of this 
muscle is one branch of the large nervous stem which passes laterally 
from the m. ambiens into the inner head of the m. femoro-tibialis 
(m. rectus internus femoris). 
The m. femoro-tidialis (mm. vasti or m. crureeus) consists of three 
heads. The inner one (m. rectus internus femoris) is the biggest 
and most distinct ; it arises from the whole inner and hinder aspect 
Deeper adductor muscles of the right thigh of Pterocles arenarius 
of the femur, and is inserted, independently of the others, into the 
anterior crest of the tibia. The middle head is also very fleshy, 
arises from nearly the whole of the anterior aspect of the femur, 
takes up the distal part of the m. ilio-tibialis, and is inserted into 
the patella and into the head of the tibia. The third or outer head 
is quite separate from the others, and is inserted into the outer edge 
of the caput tibiee by the help of the ligamentum tibio-patellare. 
All these three heads are supplied by nerves from the crural 
plexus. 
The m. ilio-fibularis (m. biceps) takes its origin from the lateral 
