. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. 244. Camera lii- cida outline, greatly magnified, of a sec- tion of the muscular coating of poison sac of Epeira domicilio- rum. Fig. 246 shows the poison sac, gland, and one of the fangs of the Mason spider (Nemesia cementaria) as dissected by Blancliard.^ 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 formid
. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. 244. Camera lii- cida outline, greatly magnified, of a sec- tion of the muscular coating of poison sac of Epeira domicilio- rum. Fig. 246 shows the poison sac, gland, and one of the fangs of the Mason spider (Nemesia cementaria) as dissected by Blancliard.^ 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 are here very manifest. They are situated near the point of the inner surface, and are of the shape represented in the 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. Ricliard 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 maxillse, 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 po
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
