108 ANNALS NEW YORE ACADEMY OF SCIENCES 



formation of the digastric and that the anterior belly is the detraliens 

 mandibulae, a muscle related to the stylohyoideus. 



Chaine (1914) thought that the digastric came from a muscle that 

 originally stretched from the jaw to the sternum, that it lost its hold 

 on the sternum and moved first to the vertebrae and then to its hold on 

 the mastoid. He accounted for the tendon between the bellies of the 

 digastric by assuming that it was a remnant of the segmental areas found 

 in primitive muscles. 



Dobson does not consider the digastric. 



Futamura (1906, 1907) had some interesting ideas on the origin of 

 the digastric of man. In the first paper on the digastric of man he says : 

 "The digastric is at first entirely supplied by the nervus facialis ; later, as 

 the anterior belly becomes constricted off from the jDosterior, the former 

 obtains its motor nerve secondarily from the nervus mylohyoideus" 

 (translation). He recants this in a later paper (1907) as follows: 



Der proximal Teil des Digastricus teilt sicli in zwei Teile deren vorderer 

 am Relchertschen Knorpel iuseriert, deren hinteren um die hintere Seite des 

 Knorpels herum ventralwarts verliiuft und am ventralen Ende des Meckelschen 

 Knorpels iuseriert. Der Muskel wird von zwei Nerven bereits innerviert ; 

 N. facialis und N. mylohyoideus. Beim Menclien glaubte icli aussprecheu zu 

 diirfen dass die zwischenseline an der doppelten Innervieruug des Muskels 

 schuld sei. Das kann aber doch nicht der Fall sein, well beim Schwein, bei 

 dem der Biventer keine zwischenseline besitzt, doch die zweifache lunervierung 

 nachzuweisen ist. 



Gegenbaur (1898, p. 632) held that the anterior belly of the digastric 

 came from the mylohyoid by splitting. He took the anterior belly from 

 the mylohyoid and the posterior belly from the depressor mandibulse of 

 the reptiles. He cited the horse with its peculiar condition, where there 

 is a secondary insertion of the posterior belly on the angle of the mandi- 

 ble, as an indication of this. 



His (1885, p. 92) derived the digastric from the sterno-cleido-mastoid, 

 which he separates into two parts : the mylohyoideus and the outer tongue 

 muscles. He derives the anterior belly of the digastric from the super- 

 ficial layer and the posterior belly from the deep layer of the sterno- 

 cleido-mastoid. 



Leche (1889) had the same idea as Futamura and thought that the 

 digastric was a muscle with a single nerve and that it acquired, second- 

 arily, a second supply from the trigeminus. 



Eouviere (1906) derived the anterior belly from the same origin as 

 the geniohyoid and says that in the fishes, amphibians, reptiles and birds, 

 only the anterior belly is present. He derives the posterior belly from 



