MUSCULAR SYSTEM 



of resemblance to man. Normal structures of certain of the 

 other Primates occur in man as fairly frequent variations (see 



Fig- 39)- 



In man, as in the Primates and gorilla, we sometimes find a 



flat, triangular muscle extending from the m. lat. dorsi through 

 the axilla to the m. pectoralis maj., supplied in the great majority 

 of cases by branches of the plexus brachialis. 1 



Other rudimentary muscles in man and the anthropoids are 



M. masseter 

 M. styloglossus 



M. digastricus 

 M. stylohyoid 



M. splenius cap. 



M . sternocleidomastoid 

 M. levat. scap. 



M. scalen. post. 

 M. omohyoideus 



M. mylohyoideus 

 M. disgastricus 

 M. hyoglossus 



M. thyreopharyngeus 

 M. omohyoideus 

 Glandul. thyroidea 

 M. sternohyoideus 



M. sterno-thyreoiders 



M. steonocleidcmast 



Pars ftemalis 

 Pars clavicularis 



Anterior scalene fossa 

 M. scalenus anter. 

 Posterior scalene fossa 

 M. scalenus medius 

 FIG. 40. Anterior muscles of the human neck. (Heitzmann-Zuckerkandl.) 



the m. palmaris and m. plantaris, and still more regressive are 

 the mm. interossei pedis, which are divided into plantares and 

 dorsales. In certain phases of the embryonic development 

 they are still plantar as they are in the apes and in most of the 

 lower mammals. The change to the dorsal position, as illus- 

 trated in man, and to a lesser degree in the orang and inuus, 

 determines the retrograde metamorphosis of these muscles. 



1 Ludwig Tobler, Inaug. Dissert., Leipzig, 1902. 



