129 



Taking, then, the trifurcate transverse process of the human 

 lumbar vertebra, and supposing each division to be prolonged, 

 we should have in the anterior the true transverse process, which 

 would articulate with a rib, if this were present, while the second 

 and third would form posterior intervertebral foramina, though 

 not homologous with these foramina in the neck, and perhaps 

 not even with those of the sacrum ; in which last they open out- 

 side of the articulating processes, making the wings of the 

 sacrum transverse processes against which abut the iliac bones 

 (or ribs.) But Owen considers the ilium as only the distal end 

 of the pelvic rib, the proximal portion being included in the 

 wings of the sacrum ; in this case, the sacral canal would be 

 homologous with the cervical vertebral canal, being formed by 

 the forks of the sacral ribs abutting against rudimentary poste- 

 rior transverse processes, as in the neck ; and from these forks 

 the ascending and descending processes, as in the neck of the 

 Alligator, would unite above and below, thus making the ante- 

 rior and posterior vertebral foramina, as well as the vertebral 

 canals, homologous in the neck and in the sacrum. 



The human skeleton is the worst that can be selected to prove 

 any point of philosophical anatomy. This is well exemplified in 

 the above instance ; for it would be impossible to arrive at Wil- 

 son's conclusions from the examination of almost any other ver- 

 tebrate skeleton. That the lumbar vertebrae do not develop ribs, 

 and that their transverse processes are in a serial line with the 

 dorsal, could not be better shown than by the skeleton of the Al- 

 ligator, in which they are simple and uncomplicated by tubercles 

 of any kind. 



The President exhibited a cast of a Mastodon's tooth, an 

 allusion to which he had happened to meet with some 

 years since. 



It had been dug up from the banks of a stream about twelve 

 miles distant from Baltimore, under the direction of Dr. Ducatel, 

 State Surveyor. After having possessed it a considerable time, 

 Dr. D. showed it to Mr. Charlesworth, who judged it to have 

 belonged to Mastodon longirostris. Sir Charles Lyell having 

 seen it, was disposed to believe it to be a tooth of M. angustidens, 



PROCEEDINGS B. S. N. H. 9 FEBRUARY, 1852. 



