M. Dumeril on the General Movements o) Serpents. 237 
excited by an impetuous ardour of courage and unwonted energy. They 
become furious at the sight of an animal which they wish to make their 
prey. In an instant, and with the speed of an arrow, they dart upon it 
with an open mouth, in front of which are arranged the sharp points of 
some elongated and curved teeth, and throughout the whole length of 
these runs a canal or groove affording a passage for a venomous humour 
which is introduced into the flesh. This is an active poison secreted for 
the purpose, and reserved in a small bladder which nature has protected 
with wonderful foresight. Penetrating beneath the skin, these poisoned 
darts deposit there a small quantity of this deleterious humour, which, 
soon absorbed, is not long in producing divers destructive effects, either 
suddenly paralyzing the mavements of the animal wounded by this sim-= 
ple sting, or throwing it into a lethargic sleep, happily, perhaps, thus 
releasing it from pain by the loss of sensibility, but in every case placing 
it out of its power to escape death, and avoid the destruction become 
necessary for the preservation of the serpent, which had no other resource 
but this to obtain the mastery over it in order to feed on its flesh. 
We shall attempt to describe the forms and structure of the organs 
which, in serpents as well as in all other animals, produce the various 
movements which their locomotion requires. We shall then indicate the 
varied circumstances which determine the diversity of this action. 
The general form and dimensions, in every sense, of the body of ser- 
pents are determined by the number, always considerable, of the bony ~ 
pieces which constitute the whole of their skeleton, that is to say, by the 
vertebrae and the ribs. This spine, however, is most simple and uniform, » 
because it supports neither sternum, pelvis, nor articulated limbs, In 
respect to the bony parts subservient to movement, it may be said that, 
of all vertebrated animals, the ophidians are those whose skeleton is 
longest in proportion to its diameter, and composed of the most moveable 
pieces, perhaps the most numerous and likest each other. 
The spine of serpents represents in the interior of the body a solid 
axis, which serves as a base of support to the general movements ; while 
at the same time its separate pieces, although extremely moveable upon 
themselves, and of very firm texture, transmit to each other the impul- 
sions they receive in the different regions in the length of the trunk. 
This insularity or independence of the vertebral column presents, in 
this respect, a very different mechanism from that found in other animals 
provided with an interior skeleton. In fishes, for example, the vertebree 
receive and support unequal fins, which represent oars in swimming ; 
then, in all the mammifera, birds, and the greater part of other kinds of 
reptiles, the spine constantly serves as a support to the bones of the limbs, 
and other solid organs designed to produce the motions of the body, 
when such accessory parts occur in their skeleton. 
The character common to all the vertebree of a serpent, and which 
may be considered as essential, is inscribed on the central region of these 
VOL, XXXII, NO. LxIy.—aprin 1842. R 
