THE MYOLOGY OF THE DOG. 417 



a y with tlie apex (tlie articulation between tlie two) 

 downwards. The claws are, consequently, raised from the 

 ground, the foot resting partly on a thick integumentary 

 pad, which lies beneath the basal phalanges ; and, partly, on 

 the under siirfaces of the joints between the middle and 

 the distal phalanges. The distal phalanges are kept bent 

 upon the middle ones by elastic ligaments, which pass from 

 one to the other, and which antagonise the action of the 

 long flexors. The Dog, therefore, possesses the mechanism 

 for the retraction of the claws, but its action is not suffi- 

 cient to protect them from wear. Fabellce, or sesamoid 

 bones developed in the tendons of the gastrocnemius, lie 

 behind the condyles of the femur. The fibula is thin and 

 closely ax^plied to, but not ankylosed with, the tibia. The 

 hallux is usually rudimentary; only the metatarsal, and 

 the basal phalanx, being represented by two small ossicles. 

 In some breeds of dogs, however, the hallux is f iiUy deve- 

 loped. 



In the myology of the Dog the insertion of the tendon 

 of the external oblique muscle of the abdomen presents 

 some interesting peculiarities. The outer and posterior 

 fibres of this muscle end in a fascia which is partly con- 

 tinued over the thigh as fascia lata, and partly forma an 

 arch (Poupart's ligament) over the femoral vessels ; by its 

 inner end it is inserted into the outer side of a triangular 

 fibro-cartilage, the broad base of which is attached to the 

 anterior margin of the pubis, between its spine and the 

 symphysis, while its apex lies in the abdominal parietes. 

 The internal tendon of the external oblique unites with the 

 tendon of the internal oblique to form the inner pillar of 

 the abdominal ring, and is inserted into the inner side of 

 the triangular fibro-cartilage. The pectineus is attached to 

 the ventral face of the cartilage; the outer part of the 

 tendon of the rectus into its dorsal face ; but the chief 

 part of that tendon is inserted into the pubis behind it. 

 This fibro-cartilage appears to represent the marsupial bone, 

 or cartilage, of the Monotremes and Marsupials. 



The trapezius and the stern omastoid coalesce into a single 



