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 pi. ischiadicus, but together with the m. ol)turator, 

 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 distal one. 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. caudse ilio-flexorius (femoral portion ==" accessory 

 part"). The inner layer arises from the lateral margin of the distal 

 tv/o 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. peroueus 

 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. iii. 



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 Euplocanms prcelata, but wanting in Gallus 



