. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. SKELETON. 645 just as the first thoracic rib (7, 8, Jig. 465.) itself iloes; and, in this particular, the clavi- cle is like the rib. The sternal half" of the cla- vicle (bjig. 465.) and the sternal half of the first rib (7, 8) are therefore as identical one with the other as the sternal halves of any other two thoracic ribs of serial order. But I see that while the ribs join the dorsal vertebrae behind, the clavicle joins the acromion pro- cess of the scapula laterally. In this latter particular the clavicle differ
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. SKELETON. 645 just as the first thoracic rib (7, 8, Jig. 465.) itself iloes; and, in this particular, the clavi- cle is like the rib. The sternal half" of the cla- vicle (bjig. 465.) and the sternal half of the first rib (7, 8) are therefore as identical one with the other as the sternal halves of any other two thoracic ribs of serial order. But I see that while the ribs join the dorsal vertebrae behind, the clavicle joins the acromion pro- cess of the scapula laterally. In this latter particular the clavicle differs from the rib. Now, granting this to be a well-marked spe- cific difference between rib and clavicle, I still maintain that there is as broad a difference ex- isting between clavicles of mammals and birds; and also between clavicles andcoracoid bones. If change of place at one end from vertebra to acromion process be enough to distinguish clavicle (a, b Jig. 465.) from rib (7, 8) in the mammal body, so must change of place be sufficient to characterise the bone named cla- vicle («Jig. 466.) in the bird from the bone so named in the mammal, for the former does not join the sternum (f,Jig- 466.), and the latter does abut against that bone. And true it is that the bone named coracoid (d,Jig 466.) in the bird joins the sternum (/), like a true mammal clavicle, but yet is not considered the clavicle, because its scapular end (e} joins another process than the acromion. It ap- pears, therefore, all circumstances considered, that the mammal clavicle (a, b,JigA(j5.) is as homologous to the rib (7, 8) in sternal re- spect (c, d) as it is to the bird's so-called cla- vicle (a, Jig. 466.) in scapular respect (c, b") ; and at the same time it appears that the coracoid bone (d,Jig. 466.) of the bird is as similar to the mammal clavicle (a, b,Jig. 465.), and mammal rib (7, 8) in sternal junction, as the bird's clavicle (a, fig. 466.) is to the mam- mal clavicle (ft, fig. 465.) in acr
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