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88 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
irregular forms. To the naked eye or under a common hand glass the 
beads often show as quite regularly arranged globules of two or three 
sizes. (Fig. 85.) 
These two opinions are very deeply seated in the popular mind: first, 
that spiders are able to shoot out from their spinnerets lines or rays; 
second, that they are able to retract within the abdomen the lines 
Elasticity which they spin. In the former case the delicate filaments are 
eect ejected from the spinning tubes as liquid silk, but the movement 
Lines. ons : : 
of the air is the means by which they are borne swiftly aloft or 
outward from the spinnerets. There is no ground in fact for the latter 
opinion, although it is not strange that casual observers should be deceived, 
as the optical illusion, for such it is, is very complete. The illusion is 
occasioned by two causes: the first is the action of the spider which in 
ascending a dropped line, for example, gathers up the thread under her 
so0000es0ee0vedrvoworvoreos JAWS, as she goes, in a little flossy ball so delicate 
as to escape ordinary observation. The other cause 
20000ce0000 0c 00000000 is the extreme elasticity of the line, which may be 
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Rea ae ees, extended greatly by the application of a slight force, 
pact Seetanpenieniee and on its removal will contract proportionately. 
7eOve- 0-000 Dv00o0— 
absabe ee One who has carefully watched the movements of 
e0-000-00-.000000~ Orbweavers while laying in their spirals must have 
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observed, what Blackwall has already noted,! that in 
~Orr@ore@v0Ge0Ge00-— passing from one radius to another the viscid line 
eQoo@veOveOscaooo. 18 usually drawn out to a much greater extent than 
Fic. 85. Appearance of beads 1S necessary to connect the two. Taking the last 
to the eye. spiral cross line, after its formation, Fig. 80, iii—iii 
prolonged, as the base of a triangle, the line is actually drawn out before 
it becomes taut and is fastened as at iii—x, ab, occupying thus two sides 
of the triangle. I have seen the line thus stretched until it certainly was 
nearly if not quite twice the length finally assumed. This elasticity is of 
course of immense advantage in the preservation of the snare under the 
struggles of vigorous insects entrapped within it, as well as before the vio- 
lence of wind, and beneath the weight of dew and rain. One may easily 
assure himself of this elasticity by touching some object to a single viscid 
string and drawing it out until it snaps. He will find that the united 
length of the two lines thus expanded will often be as much as four, six, 
or even eight times the length of the original line. 
But there results from this elasticity another advantage which I believe 
has not heretofore been noted. It presents in part an explana- 
Forma- tion of the formation of the beads, a point which has been 
ors of much discussed and never yet fully explained. The spiral line as 
eads. ; : : ‘ ate 
emitted from the spinnerets is covered with the viscid matter 
of which the beads are composed uniformly distributed over its surface. 
1Spiders of Great Britain and Ireland, Intr., page 10. 
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