. 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. OHAPTEE XYI. EFFECTS l^^D USES OF SPIDER POISON. What are the effects of spider venom? Nothing connected with the life history of spiders has given rise to greater diversity of opinion than this question. The well nigh universal belief is that all spiders Current ^^^ ^^^^^ poisonous and their bite apt to be serious and even ' fatal to human beings. It is this, doubtless, which maintains the most unjust popular dread of and host
. 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. OHAPTEE XYI. EFFECTS l^^D USES OF SPIDER POISON. What are the effects of spider venom? Nothing connected with the life history of spiders has given rise to greater diversity of opinion than this question. The well nigh universal belief is that all spiders Current ^^^ ^^^^^ poisonous and their bite apt to be serious and even ' fatal to human beings. It is this, doubtless, which maintains the most unjust popular dread of and hostility to these useful animals. On the other hand, naturalists have been generally inclined to an opin- ion quite the reverse of the popular one, and have held spiders as harm- less to man. Let us first inquire what light anatomy can throw upon the subject. More than two hundred years ago Leeuwenhoek gave a substantially cor- rect description of the fang of a spider, pointing out the small aperture through which the liquid poison is emitted. Since that time. the poison apparatus has been frequently described, and any Indica- ^j^g ^j^j^ ^ microscope can easily tions of g,^^j . himself of the facts. What- Anatomy. •' , ., jv , n .1 ever may be the effect 01 the secre- tion from the poison glands of spiders, it is certain that the organs and armature secret- ing and conveying the venom are formida- ble enough to suggest the idea of injury to Fio, 241. View of the faices (fx) and fangs crcaturcs affcctcd thereby. The fangs of Ar- :L^r:^:'^::tJ:Z,Z:Zl &ove cophinana arc shown in Fig. 241, where shown in outline, and the opening (o) in they are enlarged about fifteen times. The the fang is shown. X16. mandiblcs from which the drawing was made were taken from a nearly adult female. The falx, fx, was about two mil- limetres long and one millimetre wide. The fang itself was about one millimetre in length. When examined under the microscope it showed very clearly the matrix in which
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
