774 



5104. The tenth dorsal vertebra. 



It shows an increase in the size of the body, and of the neural spine. The posterior costal 

 surface is replaced by a non-articular tubercle. 



5105. The eleventh dorsal vertebra. 



The whole vertebra is increased in size, but the di- and zyg-apophyses are not so in the 

 same degree. There is only the anterior pair of costal surfaces upon the centrum. 



5106. The twelfth dorsal vertebra. 



This is characterized by a marked increase of the antero-posterior extent of the neural 

 spine. The metapophysis is more distinctly recognizable, projecting forwards from the 

 diapophysis. 



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5107. The thirteenth dorsal vertebra. 



In its principal characters it resembles the last dorsal of Man ; for instance, in the distinct 

 and well-developed metapophyses, which are thicker and longer in the Chimpanzee ; also in 

 the narrower and longer posterior part of the neural arch, concomitant with the change of 

 position of the posterior zygapophyses. The diapophysis still shows, in the Chimpanzee, an 

 articular surface for the tubercle of the thirteenth rib. The neural spine is longer and larger 

 than in Man, especially in its antero-posterior extent. 



5108. The first lumbar vertebra. 



This vertebra, which answers to the second lumbar vertebra in the Orang and Man, differs 

 from both in the superior length and size of the neural spine. The metapophyses project 

 from the upper and outer part of the anterior zygapophyses, from which they are separated 

 by a narrow groove. There is a feeble rudiment of anapophysis from the back part of the 

 long and depressed diapophysis. 



5109. The second lumbar vertebra. 



The metapophyses still continue to be separated by a groove from the anterior zygapophyses. 

 The neural spine is more expanded at its broad flattened termination. The centrum is some- 

 what augmented in size. 



5110. The third lumbar vertebra. 



In this vertebra the diapophysis is shorter and thicker, and the anapophysial tubercle 

 larger and more distinct at its back part. There is a slight increase in the size of the 

 centrum. 



