128 PROFESSOR OWEN ON THE ANATOMY OF 



Slernoglossus. — This remarkable muscle arises fleshy from the lateral border of the 

 dilated xiphoid and last sternal bone, and from its junction with the last two true ribs. 

 The origin (PI. XXXVIII. fig. 2, e) is at first triangular, but soon assumes a flattened 

 shape, six lines broad by two lines thick, the muscle gradually diminishing in breadth, 

 as it extends forwards, without losing thickness. Linear tendinous intersections {ib. f, f) 

 mark the part of the muscle within the chest ; the first occurs about two inches and 

 a half from the origin, and is bent with the angle turned forward ; the second, about 

 two inches in advance, crosses the muscle obliquely ; the third, at about the same 

 interval, sends a shght angle forward ; the fourth is an angular intersection, with the 

 point turned backward on one side and forward on the other side of the muscle. 

 From this point the sternoglossus passes forward, emerging from beneath the manu- 

 brium sterni as a simple fleshy muscle (PI. XXXVIII. figs. 1 &2, g), five lines broad 

 and from two to three lines thick. Opposite the hyoid it is perforated by a lingual 

 artery : between four and five inches in advance it is perforated by the lingual nerve 

 [ih. fig. \,u,u); and here it begins to give off, or its inferior stratum is resolved into, 

 flattened fasciculi of fibres which decussate or combine with those of the opposite 

 muscle, h, h. About six inches in advance of the basihyal these fasciculi spread over a 

 dilated membranous portion of the buccal cavity, at the lower part of which the base 

 of the tongue is situated: and here they converge and blend with corresponding flattened 

 fasciculi, o', o', sent off from the lower part of the genioglossi, as these pass backward to 

 the base of the tongue. The main continuation of the sternoglossus, which is concealed 

 by the subgular fasciculi, forms a rounded slender muscle (i, i, fig. 2), which raises the 

 buccal membrane so as to form the back part of the fraenum lingua', and penetrates, 

 or forms, the back part of the base of the tongue, and a great proportion of its sub- 

 stance. 



Genioglossus. — This muscle (PI. XXXVIII. m, n, o) has a complex origin, by a middle 

 portion, from the short symphysis mandibulae, m, and by a flattened penniform series 

 of fibres, from the lower border of the mandibular rami for the extent of four inches 

 behind the symphysis, ?i, n. The symphysial origin is round and slender, and belongs 

 more directly to the proper tongue-muscle : the ramal origins seem to be the more 

 special fixed point of the subgular fasciculi. The fibres of the ramal origin, n, n, 

 pass obliquely backward and inward, converging to a middle raphe, to which the 

 symphysial origin closely adheres. The two origins of the muscle are blended into one 

 for about three inches beyond the point of attachment, in which extent the muscle 

 forms a moderately thick depressed mass along the middle of the under part of the 

 mouth. It then begins to expand, and to detach from its under surface those subgular 

 fasciculi, o', o', which diverge and unite with the corresponding dismemberments, h, h, 

 of the sternoglossi. The main part of the genioglossus enters, as a single muscle {ib. 

 fig. 2, o), the fore part of the base of the tongue, carrying into the floor of the mouth 

 a fold of buccal membrane forming the fore part of the frajnum linguae. Between the 



