17-J /'///: ARTICULATIONS. 



up with tho internal and superficial tibio-tarsol ligaments in diverging down- 

 wards to the scaphoidcs, tho groat cuneiform bone, and the upper extremity 

 of the principal metatarsal bom-. 



4. Tho posterior tarso-mctatarsal ligament is a vast, very strong, and very 

 complicated fibrous arrangement, which binds, posteriorly, all the tarsal 

 bones, and also fixes them to tho throe portions of tho metatarsus. This 

 band, which is crossed by several tendons and by tho artery and vein lodged 

 in tho cuboido-scaphoido-cunean canal, is continued below by tho tarsal 

 stay of the perforans tendon. It therefore closely resembles tho posterior 

 carpal ligament. Its posterior face is covered by the tendinous synovial 

 membrane lining the tarsal sheath for tho passage of the perforans tendons. 

 It is confounded, on its sides, with the calcaneo-metatarsal, and the internal 

 and superficial tibio-tarsal ligaments. 



5. An interosssous ligament, attached to the four bones composing this 

 articulation. 



It is provided with a particular synovial membrane which always 

 communicates, in front, with the tibio-tarsal capsule. This membrane is 

 prolonged, superiorly, between the calcis and astragalus, to lubrify two of 

 the facets by which these bones come into contact ; and, in addition, it 

 descends between tho cuboid and scaphoid bones to form a third pro- 

 longation for the anterior cuboido-scaphoid arthrodia. 



Movements almost null. 



TARSO-METATARSAL ARTICULATION. This joint, formed by the meeting of 

 the three tarsal bones the cuboid and the two cuneiforms with tho three 

 bones of the metatarsus, is fixed by tho lateral superficial ligaments of the 

 tibio-tarsal articulation, the calcaneo-metatarsal ligament, those which have 

 been named the astragalo-mctatarsal and tarso-metatarsal, and by a strong 

 interosseous ligament which naturally forms three fasciculi. 



The synovial membrane proper to this joint ascends into the small 

 anterior cuboido-cunean arthrodia, and into that which unites the two 

 cuneiform bones ; it descends to the interrneta tarsal articulations. 



Movements nearly null. 



In all the domesticated nnimals except Solipeds, the tarsal articulations offer some dilVe- 

 rential peculiarities whose study is without interest, as it is without utility. It is only 

 necessary to remark that the immobility of the tarsal joints, properly called, is less 

 absolute than in Solipeds, owing to the peculiar configuration of the articular surfaces of 

 some of the bones composing them. Thus, in the Ox, Sheep, Goat, and Pig, the calcis 

 is joined to the astragalus by a real trochlear articulation, and the latter bom is unitnl 

 to the scaphoid by a diarthrodinl joint of the same kind; a mode of articulation much 

 more favourable to motion than that of tho rXauifonn diarthrodial joint. In the !><>g and 

 Cat, the same result is obtained by the reception of the head of the astragalus into the 

 superior cavity of the soaphoids. 



In Ruminantt and the Pi<j, it is also observed that the tibio-tarsal articulation is 

 formed by the tibia and fibula in the one direction, and by the astragalus and os calcis 

 in the other. 



CHAPTER III. 



OF THE ARTICULATIONS IN BIRDS. 



THE study of the articulations in birds will only Brrcst us for a few moments, as it 

 will be confined to some r marks mi the intervertehral oodpito-atloid and temporo- 

 maxillary joints, the only ones exhibiting a special conformation worthy of nttention. 



Intiri-i rl>t,riil urtii-itliti'mix. The -Mvat ni"l>ility of the IK ok of birds is not only due 

 to the fart of its length, r. latively i-on.-iden-d, but also to the peculiar manner in which 

 tho vertebra of this portion of the spinul stalk are articulated. H will be remarked that 



