1871.] MYOLOGY OF THE KINKAJOTJ. 555 



Paradoxurus and Caracal the two latter muscles are blended toge- 

 ther ; the common tendon resulting from the combined muscle divides 

 behind the extensor ossis metacarpi pollicis into two, to be inserted 

 into the radial sides of the second and third metacarpals. 



The Kinkajou has these muscles much better developed and more 

 perfect than the Paradoxurus and Caracal, and more in accordance 

 with that condition which is called the average one in the human 

 subject. This is not exactly true, however ; for while the Kinkajou's 

 muscles illustrate a decided advance above that of the Caracal, Pa- 

 radoxurus, Dog, and Cat, and simulates the corresponding muscles in 

 the Primates, still the human subject leads, and exhibits in the com- 

 plexity of arrangement occasionally found in these muscles a tendency 

 towards a further grade of muscular development which is minus a 

 homologue in any other living animal. Douglas, in his 'Myographia 

 Comparata,' states that the supinator longus is wanting in the Dog : 

 I can scarcely say that it is wanting ; it is aborted ; its muscular 

 belly is decidedly present and joined with the extensor carpi radialis 

 communis. In several specimens which I have carefully examined, 

 I have detected indications of segmentation of the supinator longus 

 from its companion muscle. This was especially marked in a thorough- 

 bred Spaniel which I had the pleasure of dissecting during last winter. 



The extensores communis digitorum and carpi ulnaris and the 

 supinator brevis present the usual arrangement. 



The extensor minimi digiti divides into three tendons, to be distri- 

 buted to the third, fourth, and fifth toes, joining the tendons of the 

 common extensor on their ulnar sides. 



The extensor ossis metacarpi pollicis is a large fleshy muscle ; it 

 is inserted into the trapezium and pollex metacarpal base. 



The extensor indicis divides into two tendons : the radial one is 

 distributed to the pollex, and constitutes its only phalangeal extensor ; 

 the ulnar one joins the ulnar side of the common extensor tendon to 

 the second digit, to be inserted along with it. 



Muscles of the Hind Limb. 



The psoas parvus arises fleshy from the front and sides of the three 

 upper lumbar vertebrae, and from the disks between the first and 

 second, and second and third. The tendon of insertion is broad and 

 flat, and commences on the superficial aspect of the upper part of 

 the muscle, the muscular fibres being prolonged upon the under 

 surface of the tendon for nearly half its length. It is inserted into 

 the ilio-pectineal eminence and brim of pelvis immediately posterior 

 to the origin of the pectineus. It lies superficial to the quadratus 

 lumborum and psoas magnus, simply separated from the latter by 

 areolar tissue. 



The ilio-psoas. The psoas magnus arises from the front and 

 sides of the bodies of the three lower lumbar vertebrae and their disks 

 by fleshy fibres, and from the sacral surface and the posterior half 

 of the pubic border of the ilium, where it becomes continuous with 

 the iliacus. The latter arises from the iliac surface of the bone as a 



