Apparatus of Snakes. 
197 
union in the mesial line of the ft lips’' already alluded to. 
3. The poison gland and duct. The gland is situated 
behind and rather below the level of the orbit, and is best 
seen by making a longitudinal incision through the mucous 
membrane, external to the upper jaw, and dissecting from 
below upwards. It is very readily exposed, being only con¬ 
nected with the superjacent tissues by a few bands on its ex¬ 
ternal margin, whilst the greater part of its surface is unat¬ 
tached, and freely moveable underneath the skin. Its size of 
course varies according to that of the snake, but if this be 
about five feet in length, the gland will be found to be about 
half the size of a small bean. It is of an ovoid figure and 
consists, externally, of a dense fibrous membrane, possessing 
in the recent state an almost pearly lustre; and internally 
of a soft pulpy mass, the secreting apparatus of the poison. 
The duct is of the same structure as the gland, to the an¬ 
terior extremity of which it is attached. Under cover of the 
mucous membrane, it then passes forward underneath the 
orbit running along the upper jaw, at the head of which it 
terminates by becoming applied to the proximal orifice of the 
poison fang. On making pressure on the gland the duct im¬ 
mediately becomes distended and a drop of the clear, glairy, 
venomous fluid is seen to make its appearance at the distal 
orifice of the fang. This is very prettily shewn if the fang 
be pushed through a fold of a black silk handkerchief before 
pressure is made ; the white tooth is then well isolated and 
in good relief, and the process is seen most distinctly. 
The provision made by nature for forcing the poison out of 
the gland, is at once simple, elegant, and effectual. It con¬ 
sists in a single muscle, which rises from a ridge of bone 
that sweeps in a slightly curved line from behind the orbit in 
front to the posterior part of the skull, and formed anteri- 
orily by the posterior frontal, and behind by the junction of 
the two parietal bones. The anterior fibres of the muscle 
descend downwards and somewhat backwards, and are in- 
