the Chimpanzee and others of the Primates. 343 



it is absent in the latter genus (Cyclopaidia of Anatomy and 

 Physiology, art. "Quadi-umana," vol. iv. p. 203). The spinal 

 accessory nerve pierces the muscle in the Chimpanzee as in 

 man. The omo-hyoid is extremely feeble, but biventral, and, 

 as usual, scapular in origin ; Vrolik states that it is absent in 

 Inuus and Cynocephalus ; but I have found it in the Inuus and 

 in Macacus cynomohjuSy as well as in Cynocephalus porcarius 

 and hamadryas. Inscriptiones tendineas cross the bellies of 

 the sterno-hyoid and thyroid muscles, which are otherwise as 

 in man. 



Of the laryngeal muscles none were far removed from the 

 human type. No trace of the muscle described by Eschricht 

 in the Hylohates alhifrons (Archiv fur Anat. 1834, p. 218) was 

 present. No kerato-cricoid, triticeo-glossal, or other of the 

 cm'ious aberrant fascicles so frequently found in the neighbour- 

 hood of the human larynx could be seen, except a small kerato- 

 arytenoid muscle on the left side : this muscle is described as 

 an anomaly in man by Professor Gruber, under the appellation 

 " Schildknorpelhorn-Giessbeckenknorpelsmuskel." 



Digastric. I did not notice a splitting of its broad anterior 

 belly, as described by Wilder ; but that such should be the 

 case is what one might expect from the analogy of other 

 Quadrumana : the anterior belly is split in some Cercopitheci ; 

 and in the Macacus rhesus^ cynomolgus^ and nemestrinus 

 the mesial tendon is prolonged from one side to the other 

 above the hyoid bone : this I have found the commonest 

 arrangement in Quadrumana. The thyro-hyoid, genio-hyoid, 

 and other lower-jaw muscles were matted together by the 

 products of the inflammation of the lower jaw, and were con- 

 sequently undistinguishable. 



The muscles of the back were carefully dissected, and exhi- 

 bited the following points : — The trapezius extended down to 

 about the tenth dorsal sjDine^ and overlapped the latissimus 

 dorsi, but was very thin and indistinct at this part. Wilder 

 found it to be apparently continuous with the latissimus dorsi j 

 and Vrolik notices the same. Duvernoy found it an'anged in 

 the Gorilla as I have above described in the Chimpanzee ; and 

 I found the same arrangement in an undetermined species of 

 Macacus ; in general, however, in the lower monkeys the in- 

 ferior part of the trapezius is with difficulty separable from 

 the latissimus dorsi, as it becomes thinned and gradually lost 

 below. The human character of the rhomboidei (being with- 

 out the occipital slip) has been noticed by the various authors 

 whose dissections have been published ; the major and minor 

 portions are scarcely divisible, as very often occurs in man. 

 The levator anguli scapulae is also peculiar for its possessing 



