1882.] DR. GADOW ON THE ANATOMY OF PTEROCLES. 315 



muscles of the shoulder-girdle I am indebted to Prof. Fuerbringer for 

 the information that Ptei-ocles approaches nearer to the Pigeons than 

 to the Fowls. 



Mm. iliaci externi {mm. glutei). — This group in Pterocles con- 

 sists of only two muscles, an anterior and a posterior. Of these the 

 latter is the larger ; it arises from the broad latero-dorsal plane of 

 the praeacetabular part of the ilium, and is inserted close to the external 

 trochanter of the femur. The iliac muscles have their nerve-sup])ly 

 from the crural plexus. 



M. iliacus internus. — This small muscle is comparatively long, as 

 it arises from nearly the middle of the ventral aspect of the praeace- 

 tabular ilium. It is inserted as usual, between the internal trochanter 

 and the neck of the femur. 



M. sartorius. — Flat and very broad, from the greater part of the 

 lateral and dorsal margin of the praeacetabular ilium. The muscle is 

 partly blended with the m. iUo-tibialis at the distal third of the 

 thigh ; the rest passes over the patella as a flat but nevertheless 

 rather fleshy strip, and then extends into part of the head of the 

 m. extensor digitorum communis. The muscle is supplied by nerves 

 from one of the first branches of the crural plexus. 



M. ilio-tibialis (m. quadratus femoris). — This muscle is rather 

 feebly developed; it arises with an aponeurotic sheet, which super- 

 ficially covers the mm. iliaci externi, and which also takes origin 

 from the regio posttrochanterica of the ilium. The muscle is com- 

 pletely blended with the m. femoro-tibialis, with the m. gluteus 

 posterior, and with the m. sartorius. It is inserted together with 

 the tendon of the mesial and external part of the ra. femoro-tibialis 

 into the head and rest of the tibia. Nerve-supply from the crural 

 plexus. 



The m. gluteus posterior + '«• tensor fascice lafce (m. tensor 

 fasciae latae) arises rather fleshy from the lateral plane of the postace- 

 tabular part of the ilium, and is inserted indirectly into the head of 

 the tibia by being attached to the distaljpart of the m. ilio-tibialis. 

 Nerve from the ischiadic plexus. 



The m. gluteus anterior (m. gluteus quartus) is very small ; its 

 muscular part consists of only a few fibres. Its aponeurosis arises 

 from the space left between the origin of the m. iliac, ext. post, and 

 the antitrochanter. Its short but broad and flat tendon runs over the 

 external trochanter, passes the tendons of the external iliac muscles, 

 and is inserted just distad from their insertion into the outer aspect 

 of the femur. The nerve to this muscle is given off from the pi. 

 ischiadicus ; it passes round behind the antitrochanter out of the 

 ischiadic foramen. 



The ?«. ambiens arises with a short and distinct tendon from the 

 pubic spine ; its roundish and somewhat ribbon-shaped belly tapers 

 out into a long slender tendon, which, after partly piercing that of 

 the m. femoro-tibialis, passes over the knee into its outer side and 

 then supports one of the heads of the m. flexor perforatus digiti iii. 

 Between the proximal part of the ambiens muscle and the inner 

 trochanter of the femur, that long nervous branch which is sent off 



