575 



3460. The second lumbar vertebra. 



The diapophyses have much increased in length. The metapophyses are still distinguishable 

 from the anterior zygapophyses ; the position and aspect of which become much changed by 

 the development of the former. 



3461. The fifth lumbar vertebra. 



The diapophyses have increased in length, and the neural spine has diminished in height. 

 The metapophyses can no longer be distinguished from the anterior lygapophyses. 



3462. The last lumbar vertebra, with the sacrum. 



In this specimen may be observed the double interlocking joints of the coadapted zygapo- 

 physes, and the depressions above the bases of the lumbar diapophyses for lodging the pro- 

 duced extremities of the sacral zygapophyses. The sacrum consists of five vertebra, the 

 tuberous spines of which are distinct. Their diapophyses have coalesced, except at the por- 

 tions of their original interspaces reserved for the passage of the upper or dorsal divisions of 

 the sacral nerves. 



3463. The left scapula. 3464. The left humerus. 



3465. The right humerus, longitudinally bisected. 



The canal for the medullary artery commences at the fore part of the lower third of the 

 shaft, passes obliquely inwards and downwards, and terminates at the lower end of the 

 medullary cavity. 



3466. The left coalesced radius and ulna. 



The primitive division is indicated by small foramina near the two extremities of the shafts. 



8467. The right coalesced radius and ulna, longitudinally bisected. 



This preparation demonstrates the essential distinction of the two bones by their separate 

 medullary cavities. 



3468. The left metacarpus or ' cannon-bone/ 



3469. The right metacarpus, longitudinally bisected. 



It consists of the coalesced metacarpals of the digits answering to the third and fourth of 

 the pentadactyle foot. Notwithstanding the ultimate blending of the two bones apparent 



