512 ORIGINAL ARTICLES. 



The slip to the sterno-mastoid, which Duvernoy found in the Orang, 

 occurs as an accidental variety in man, as is mentioned by Theile.* 



The Glavio-trachelien, or Acromio-trachelien, arose from the clavicle 

 alone, and was inserted into the inner side of the transverse process 

 of the atlas. In the Gorilla, it has the same insertion, but it arises 

 from the acromion. f 



The Latissimus Dor si possessed much the same origin as in man, 

 but scarcely reached so far up the back. The fibres which arose from 

 the dorsal vertebrae remained distinct, and did not interlace with those 

 of the inferior portion of the muscle ; and, as they curved round the 

 lower margin of the Teres Major, they formed a distinct head, sepa- 

 rated from the rest of the muscle by a septum of dense tissue, which 

 was inserted partly into the external fascia of the arm, and partly into 

 the humerus, together with the tendon of the Teres Major. The 

 larger and inferior portion of the muscle passed on to be inserted by 

 a broad tendon, which curved round the humerus, and was inserted 

 into the inner surface of that bone an inch and a half below the bicipital 

 groove. At the distance of an inch and a half from the point of 

 insertion, a strong muscular slip, called by Duvernoy the Dorso- 

 epitrochlien, is given off, which passes down along the inner side of 

 the long head of the Triceps, to be inserted into the fascia of the arm 

 and the olecranon process of the ulna.:}; 



In the Grorilla, the Dorso-epitrochlien receives a small slip from the 

 tendon common to the Biceps and the Coraco-brachialis (Duvernoy, 

 1. c, p. 80.) In the Cebus, the tendon of the portion coming from the 

 dorsal vertebrae is not inserted together with that of the Teres Major, 

 but close to it This modification of the Latissimus Dor si appears 

 common to all the Quadrumana, and must greatly relieve the strain 

 thrown on the muscles of the arm and shoulder by the weight of the 



* Encyclopedic Anatomique, traduit d'Allemand par A. J. L. Jourdan, torn. iii. 

 p. 124. 



f This, the Acromio-basilar muscle of Vicq. d'Azyr, is eminently characteristic 

 of the lower Mammalia ; so that M. Duvernoy (second edition of Cuvier's Lecons, 

 tome i. p. 371) even says, "On le trouve dans tous les mammiferes, l'homme 

 excepte, ce qui semblerait prouver qu'il est une des conditions de la station quadru- 

 pede." Its upper attachment varies in the Mammalian series from the lower 

 cervical vertebrae (camel) to the occipital bone (rabbit). The human muscular 

 variety, which appears to make the newest approach to the development of this 

 muscle, is that observed by R. Wagner (cited in Henle's Handbuch der Systematis- 

 chen Anatomie des Menschen, Bd. I. 3te. Abtheilung, p. 24) who found an accessory 

 fasciculus of the Trapezius inserted into the Mastoid process, and remaining separate 

 as far as the Acromion. The numerous dissectors, who will be busy in our medical 

 schools during the ensuing winter, might do good service by attending to the 

 variations of the Trapezius ; and indeed of all those muscles whose attachments in 

 man differ widely from those presented by the apes — e.g. the Flexor pollicis proprius, 

 the Extensor i?tdicis,and the luferossei of the hand: the Tibialis anticus, Extcnsores 

 digitorum brevis, covimunis digitorum, hallucu longus, Flexor brevis digitorum, 

 Transversus pedis, and Tnterossei of the foot. We shall be glad to receive and to 

 record examples of such varieties. — [Eds.] 



% This muscle is clearly represented in Man by the tendinous band which, as 

 Halbertsma has shown (Henle, 1. c. p. 183) constantly connects the long head of the 

 Triceps with the Latissimus dorsi. — [Eds.] 



