652 Marvels of the Untverse 
is provided with a groove, along the edges of which are set a row of terrible teeth (see the illustrations 
on pages 651 and 652). The falces are not used in the act of taking food, but are for the 
purpose of catching prey, holding and killing it. The last operation is brought about by means 
of a rapidly-acting poison injected into the victim through a little hole at the top of the fang. 
It must therefore be clearly understood that a fly caught by a spider is almost instantaneously 
killed (which fact grasped, lessens the feeling of animosity in the onlooker), this being proved by the 
fact that if it be immediately released, as the writer has often done, and the web around it entirely 
removed, it is found to be quite dead. Not so, however, in the case of spider victims, for the poison 
does not seem to affect them in 
a like manner ; upon releasing 
one in a similar way to the fly, 
it has been found to recover 
itself rapidly and hasten away. 
Before leaving the subject of 
the falces, attention should be 
directed to the powerful muscles 
which actuate the fangs ; in the 
accompanying illustration they 
are plainly shown as radiating 
lines passing downwards from 
the fang into the base. These 
pull the fangs downward upon 
the bases, so as to lodge them 
neatly between the rows of 
teeth, thus effectively pre- 
venting the escape of the victim. 
The fangs shut completely 
down are shown on page 651. 
The eyes of a Spider are 
set in the front part of the 
head ; they are not of the com- 
pound variety found in insects, 
but are of the single type, and 
called “ ocelli.” They vary in 
number and position, and are 
Cas largely concerned in the classi- 
FHP EANGMOLLUL CN Seip ee oe ee fication of the different orders ; 
An enlarged photograph of the falx, showing the fang erect. Notice the in the photograph on page 651 
powerful muscles which drag the fang between the teeth, and so secure the Spider's they are shown specially dis- 
victim, 
ee BS 
Photo by} 
sected out. 
The palpi—with little hooks on their ends—look like short legs. They are sensory organs of 
some kind, but their exact nature is not known, much difference of opinion existing between different 
naturalists. They are seen in the full-page photograph. 
The mouth of a Spider is situated at the front of the head, in the neighbourhood of the base 
of the. falces. It contains a kind of tongue and has two very pronounced lips, an upper and a lower, 
provided with teeth. The mouth apparatus is used for sucking purposes and not for devouring, 
as a Spider apparently never eats its prey ; simply sucks it dry. 
The spinnerets at the end of the body vary in number in different species ; they are seen, in the 
) 
upper photograph on page 654, to be conical projections, each being surmounted at the tip by 
