41 
vertebra: varies to accommodate itself to this configuration, so 
that the spine cannot be extended into a straight line without dis¬ 
location of its parts. In the portion of spinal column which we 
examined, each curve consisted of about nine vertebrae. Each 
vertebra was articulated by a round head on its posterior ex¬ 
tremity to a socket in the anterior extremity of the next.* It 
i had five principal processes, one a spinous process; two anterior, 
and two posterior transverse processes. There were also small¬ 
er processes articulated with the ribs, and a sharp longitudinal 
prominence underneath. The spinous processes varied remarka¬ 
bly in shape and size, according to the part of the spine in which 
they were situated. Those occupying the top of the curve were 
very broad, and those of the bottom of the curve very narrow, 
the latter being not more than half the breadth of die former. 
The top of the spinous processes in the ascending or anterior 
* half of each elevation of the back-bone projected considerably back¬ 
ward. In the descending half, on the contrary, they projected 
forward, so as to appear as if this part of the spine were inverted. 
The space between the spinous processes was very great, amount¬ 
ing to nearly two thirds of their longitudinal diameter; a circum¬ 
stance which contributes very much to the vertical flexibility of 
the spine, being much greater than it is in the Boa constrictor, 
one of the most flexible serpents, as represented by Sir Everard 
Home in his comparative anatomy ; or than it is in the Coluber 
constrictor, which your committee have examined. The two an¬ 
terior transverse processes are long and sharp, and are received 
* This is the reverse of what Cuvier asserts of serpents in general, 
in his learned work on comparative anatomy. He states that the tuber¬ 
cle is on the anterior, and the cavity on the posterior part of the verte¬ 
bra. “ La partie anterieure du corps de la vertebre presente un tuber- 
cule arrondi demi-spherique ; et la partie postei-ieure offre, au contraire, 
une cavity correspondante ; de sorte que chacune des vertebres est ar- 
ticulee en genou avec celle qui la suit, et avec celle qui la precede. ’ 
Lemons d’anatomie comparie I. 176.—We are induced to believe that in 
the above passage the terms anterior and postei-ior must have been mis¬ 
placed. The tubercle, we think, always occupies the posterior part of 
the vertebra. 
