ZOOLOGICAL AND ANATOMICAL CHARACTERS. 
3 
The examination of the wound inflicted by a snake might 
thus, to a very great extent, enable one to judge whether it 
were poisonous or not. On the other hand, the bite of the 
Ilydrophidce might present much the appearance of the non- 
venomous terrestrial snakes; the anterior maxillary tooth or 
fang is so small and so little different from the other maxillary 
teeth, that the distinct marks of two fangs would probably not 
be present, and yet the bite might be a most dangerous one ; 
for, as Gunther says, “There cannot he the slightest doubt that 
the sea-snakes belong to the most poisonous species of the 
whole order. Russell and Cantor have ascertained it by direct 
observation: tortoises, other snakes, and fish died from 
their bite in less than an hour, and a man succumbed after four 
hours.” It is necessary that this should be borne in mind, 
although with reference to the land snakes, exceptions to this 
rule are rare. 
In the typical poisonous snakes, the maxillary bone is re¬ 
duced to a mere wedge of bone, giving support only to the 
poison fangs. The ecto-pterygoid bone is elongated in pro¬ 
portion, and it is mainly through the medium of the articu¬ 
lation of the maxillary bone with this bone that its hinge-like 
motion enables the snake to depress or erect the fang at will. 
The tooth, it is to be observed, has no independent motion, 
it moves only with the bone with which it is united, that bone 
being moved during muscular action by the pressure on it of 
the ecto-pterygoid. In the viperine snakes, in which the 
poison fangs are very large, the degree of mobility is 
remarkably great, and the snake, when irritated and about to 
strike, gives them a peculiar and independent vibratile move¬ 
ment which is very striking. In them the natural position of 
the fang is the recumbent one. When the snake strikes, and 
as it opens its mouth, the maxillary bone is pushed forward, 
and the fang is erected. The poison fangs are described. as 
grooved or perforated teeth, but, strictly speaking, they are 
not so. Like other teeth, they are solid, composed of dentine 
and cement, but they are folded over so as to form a cylinder 
in some cases ; in others an open groove. It is as though you 
took a leaf and folded it longitudinally until its edges over¬ 
lapped to form a tube, or approached each other so as to form 
a groove. The various degrees of involution are represented 
permanently in the fangs of different poisonous snakes. For 
example, in the Ilydrophidce, the fang is only so folded as to 
form an open groove ; in the Elapidce the canal is a tube; in 
the Viperida: it is even more so, all appearance of this involu¬ 
tion having disappeared. The groove or canal communicates 
at the base by a triangular opening with the poison duct; and 
the apex is open near the point. It will be seen from this, 
that the groove or perforation is external to the pulp cavity. 
The dentine of the fang is arranged so as to radiate vertically 
round the canal, and it is covered externally with a coat of 
cement, which gives its polish and hardness. The fangs vary 
much in size in different families of poisonous snakes. In the 
Viper they are very long and sharp pointed, and most formidable 
weapons from their size, having the power to inflict a deep 
wound. They are perforated from the base to the apex by the 
poison canal which runs along the anterior convex side of the 
tooth ; they are firmly anchylosed to the maxillary bone, which 
is exceedingly mobile. 
In the Elapidce the structure of the fang is similar, but it is 
relatively much smaller, and there is little or no movement in 
the maxillary bone, which is longer than in the Viperidce , and 
has sometimes one or two ordinary teeth behind the poison 
fang. It is also a most formidable weapon, independently of its 
connexion with the poison gland, but only half the size of the 
viperine fang. In the Hydrophidce the fang is still smaller, and 
the canal remains as an open groove along which the poison is 
injected into the wound inflicted. 
The amount of involution I believe varies in the Ilydrophidce ; 
for example, in the fangs of a large Enhydrina, four feet long by 
six inches in girth, I found the fangs partially grooved and 
partially closed. Excepting on close examination, the groove 
appears nearly as much closed as the Cobra’s fang. It is, after 
all, merely a question of degree, not of kind. 
The Hydrophidce or salt-water snakes are a very poisonous 
family. The bite is very dangerous notwithstanding the small 
size of the fang. 
A few words now on the formation of the Ophidian skull. 
It has three pairs of frontal bones; the two anterior form 
the anterior part of the orbit, the two median lie between them 
and the two posterior, which form the posterior boundary of 
the orbit. The nasal bones lie immediately in front of the 
middle frontal, and the inter-maxillary bone between them 
forms the muzzle of the snake. The parietals lie behind the 
post-frontals, and at their posterior angles are the two mastoid 
bones, which overlap as they articulate with them. The mastoid 
bones, which are moveable, articulate with the long and 
slender tympanic or inter-articular bones ; they articulate at the 
opposite extremity with the mandibles, each of which consists 
of three segments—the articular, the coronary, and the dentary. 
These are united in front to form the lower jaw by an elastic 
ligament; the result of this loose and ligamentous union of 
the mastoids, the tympanic and the mandibles, is to give 
great extensibility to the aperture through which the prey 
is introduced into the gullet. The upper jaw is composed 
of the pterygoids, the palatines, the ecto-pterygoids, the maxil- 
laries, and the pre-maxillary. The maxillary arch is thus made 
up of the maxillary bones, which, in the Viperidce, the typical 
poisonous snakes, are short, moveable, and furnished with one 
long tubular fang each. The non-venomous colubrine snakes, 
on the other hand, have a long fixed maxillary bone set 
with a number of non-perforated teeth, as before described. 
The maxillary bones of the poisonous colubrine snakes are 
a modification of the latter. They are longer than in the 
viperine family, and less moveable. They have a tubular 
poison fang, but it is smaller ; and they have in some cases 
one or more fixed and non-perforated teeth immediately behind 
the poison fang. Such may be seen in the Naja and Bimyarus. 
The maxillary bones articulate with the palatine, the ecto- 
pterygoid with the anterior frontal, and in the non-venomous 
snakes with the pre-maxillary. This bone varies much in form 
in different genera. 
The pterygoid articulates with the palatine, ecto-pterygoid, 
and basi-sphenoid; and in the Viper it abuts against the tym¬ 
panic pedicle, and thus influences the movement by which, 
through the ecto-pterygoid, the maxillary bone is pushed 
forward and the fang erected. The ecto-pterygoid overlaps the 
posterior portion of the maxillary at one end, and at the other 
it joins the pterygoid. The mandibular arch is composed of the 
tympanic bones which articulate with the mastoid at one end, 
and with the condyles of the lower jaw or mandibles at the other; 
this mandible on either side being, as I have said, composed 
of three segments, and the posterior part of the pterygoid, which 
—in the Viper—abuts against the end of the tympanic pedicle. 
The bones which enter into the formation of the cranial 
cavity are—parietals, basi-occipital, occipital, ex-occipital, 
sphenoid, ali-splienoid, basi-sphenoid, pre-sphenoid, and orbito- 
sphenoid; the lachrymal and turbinal bones, and vomer. 
These are connected with the maxillary arch. In the Vipers 
especially there is a prominent bony spine on the base of the 
skull, to which the longus colli muscles have a firm attachment. 
This gives these snakes the great power of striking that they 
possess. 
The muscular apparatus connected with the bones I have just 
briefly described, is next to be shortly considered, especially that 
portion of it which is concerned in the act of grasping the prey 
and inflicting the poisoned wound. 
