318 DR. GADOW ON THE ANATOMY OF PTEROCLES. [ Mar. 21, 
adjoining part of the pubis. It is inserted by means of a very strong 
tendon into the externo-posterior plane of the outer trochanter. 
Another muscle, which we may call an accessory muscle to the 
m. obturator, is very small, and arises from the most proximal and 
lateral part of the ossa pubis et ischii near the acetabulum ; its fleshy 
but short belly is separated from that of the m. ischio-femoralis by 
the tendon of the main obturator muscle. It is inserted just between 
the tendons of these two muscles. As this small muscle is not 
supplied by the pl. ischiadicus, but together with the m. obturator, 
we cannot consider it to be a representative of the gemelli muscles, 
nor of part of the m. obturator internus of mammals. But the m. 
obturator of birds, together with its accessory muscles, might corre- 
spond to the m. obturator externus of Mammalian anatomy. 
The m. pubi-ischio-femoralis (m. adductor) consists of two layers, 
a lateral and more proximal and a median or distalone. The lateral 
part is ribbon-shaped, and arises from the latero-ventral margin of 
the middle third of the spines, opposite the pubis. It is covered 
laterally by the m. caud. ilio-femoralis, and is inserted into the hinder 
aspect of the distal half of the femur, lying mesiad from the femoral 
portion of the m. caude ilio-fiexorius (femoral portion==‘* accessory 
part”). The inner layer arises from the lateral margin of the distal 
two thirds of the ischium, but not from the os pubis or the ischio- 
pubic membrane. This flat muscle forms scarcely any tendon, and 
is inserted as a broad, but flat and vertical sheet into the distal half 
of the femur, including the internal condyle, and into the hinder 
surface of the head of the tibia. 
The m. popliteus is developed as usual. 
The m. tibialis anticus consists of two heads. The external or 
femoral is represented simply by a long tendon arising from the 
anterior inner margin of the internal condyle; its short belly soon 
fuses completely with the tibial or chief head, which latter takes its 
fleshy origin from the crest and head of the tibia. The strong tendon 
of this muscle passes under the transverse ligament of the leg, and 
is inserted into the anterior or dorsal sulcus of the tarso-metatarsal 
bone, not far from the joint. The whole muscle is covered superficially 
by the m. gastrocnemius (inner head) and by the m. peroneus 
superficialis. Nerve-supply, as in all the following muscles, from 
the ischiadic nerve. 
M. peroneus superficialis.—The most superficial muscle on the 
anterior and outer side of the leg. It arises from the crest of the 
head and from the anterior plane of the neck of the tibia, and some- 
times from the head of the fibula. Its broad tendon passes round 
the outer side of the leg to the hinder aspect of the intertarsal joint, 
and then divides into two tendons: one is very broad, and forms the 
deep sheet of the susceptaculum ; the other one is much narrower, 
passes laterally over the external malleolus of the tibia, and then joins 
the tendon of the m. flexor perforatus dig. m1. 
A m. peroneus profundus was not present in my specimen of 
Pterocles. However, this muscle is subject to much variation. I 
found it well developed in Zuplocamus prelata, but wanting in Gallus 
