6o 



THORACIC AND LUMBAR VERTEBRAL [CHAP. 



processes. In two or three vertebrae the two co-exist (Fig. 

 21, B and c), resembling the upper and lower transverse pro- 

 cesses of the neck, and sometimes even meeting at their 

 extremities so as to enclose a canal. The lumbar transverse 

 processes in this case therefore are not serially homologous 

 with the transverse processes of the anterior thoracic region, 



FIG. 21 .Anterior surface of vertebra; of Sperm Whale (I'/iyseter itmcrocef>hahts), ^ . 

 A eighth thoracic ; u ninth tlioracic ; c tenth thoracic ; D fifth lumbar ; r rib ; 

 in rnetapophysis ; / upper transverse process ; /' lower transverse process. 



and with the upper transverse processes of the neck, as in the 

 former case, but rather with the lower transverse processes 

 of that region ; and yet tried by every other test, the special 

 homology of the transverse processes of the lumbar vertebrae 

 of a Dolphin (Fig 20, D /) and a Sperm Whale (Fig. 21, D /) 

 is perfectly evident. 



