ee 
270 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
Fig. 246 shows the poison sac, gland, and one of the fangs of the 
Mason spider (Nemesia cementaria) as dissected by Blanchard.' The ver- 
tical articulation of the fangs, or movement up and down, which char- 
acterizes this tribe of spiders, 
may be noted in the cut, Fig. 
247 represents the formidable 
mandibles of the large My- 
gale, popularly known as the 
“tarantula,” drawn twice the 
size of nature. The outlets 
for the poison from the fangs 
Za Pelt ate are here very manifest. They 
magnified, of a see. are situated near the point of 
rou oat va ak the inner surface, and are of 
of Epeira domicilio. the shape represented in the 
' ees figure. On one side of the 
falx is a formidable row of ten teeth. The other side is protected by a 
picket of closely placed stiff red bristles, It might be expected that such 
a formidable armature would certainly inflict a grievous hurt, whatever 
may be the case concerning the feebler armature of our ordinary familiar 
spider fauna. 
Another illustration of these organs is given at Fig. 248, which repre- 
sents the fang and falx of an immature Drassus, multiplied about twelve 
times, taken from a camera lucida drawing made by the late Mr. Richard 
Beck.2. The manner in which the falces and fangs are related to the mouth 
organs is shown at Fig. 249, which is a view from 
beneath of the cephalothorax of Epeira quadrata. 
The lip is seen at the tip of the sternum, which 
lies just under the maxille, which organs in turn 
are situated just beneath the falx. 
The moults of spiders form admirable specimens 
in which to examine microscopically the external 
character of the fang. They not only show the 
opening far more distinctly than the entire organ 
taken from the animal, but they present the fangs 
in a most favorable position for examination. 
In view of the above results, we are free to say Fra. 245. Poison gland (g), duct (4), 
that as far as the testimony of anatomy goes, itis {"* SS eon oe faite 
plain that spiders of all tribes are abundantly — more enlarged, to show the ex- 
‘5 , 5 Resto ternal opening, 0. (After Davis.) 
provided with an armature for dealing an injurious 
wound to those whom they strike. One can hardly suppose that such a 
gland as I have described, with such an attachment, is intended to secrete 
any other substance than one.which provides for the defense or nourish- 
ment of its possessor. 
pares 1 Cuvier, ‘Regn. Anim. Arachnides. ——? “Science Gossip,” 1866, page 202. 
ND, 
vel es oan i. bl > Yo ee ee ie ee eee 
