THE SNARE OF THE GIANT WOOD SPIDER. 
918 
and distinguish each separate act. She takes a position in line with the spokes 
her head is directed to the centre ; and in this attitude, with great deliberation, 
she moves sideways round and round her wheel. The Araneus, and others 
of the smaller kind, have to make use of their temporary spiral in order to pass 
from radius to radius. Between each attachment they have to run inward and 
cross over by the bridge. Not so the Nephila. She is independent of her 
temporary spiral. She need only reach across from radius to radius and pull 
herself over the spokes. 
Now each of her limbs has its special duty as she moves in the architectural 
round. Consider that her head is towards the centre, the tip of her abdomen 
close to her spiral, and that she is making her circle to the left. First look to the 
legs of the left or advancing side ; they are emploj’ed in the following way. The 
fore leg is stretched far out to the left and clutches one of the radii a considera- 
ble distance ahead. It is a long and slender limb, and near the circumference 
I see it grasp a radius as many as eight in advance. This fore limb, therefore, 
serves as an implement to pull the spider round and round her snare. Now 
look to the second leg, of course on the same side. It also is stretched out but 
the radius which it clutches in its terminal claws is only two in advance. The 
second leg draws in this radius towards the spider ; then it passes the line on to 
the claws at the tip of the third leg which is stretched out to receive it. In the 
same way the third leg passes on the line and hooks it over the claws of the hind 
leg ; and the hind leg then continues the traction until it finally anchors the line 
to the spinnerets. This last effort is a careful and decided pull. At the same 
time the tip of the abdomen is pressed down with decision upon the radius ; 
the spinnerets touch the line, and the viscid spiral is secured. But there is 
another detail ; the function of the left hind leg is not yet quite complete. Im- 
mediately after the attachment has been made, the hind leg then presses away 
the radius which before it had pulled in, and this has the effect of drawing some 
of the viscid spiral from the spider’s spinnerets. 
Now turn to the limbs of the right side. The first three do not perform any 
work quite so particularly precise. They certainly move with deliberation 
and care. They are stretched in towards the centre ; they clutch the turns of 
the temporary spiral, but they do not appear to fulfil any more precise function 
than just to support the spider in her circles round the snare. But it is other- 
wise in the case of the hind limb of this side. I have just said that the last 
effort of the left hind leg was to press the radius away from the spinnerets, but, 
after a short thrust, it then passes over the line to the care of the right hind leg, 
and this limb continues to press away the radius until sufficient of the filament 
has been drawn out. One other minute point ; the left hind leg works with 
its claws ; the right one thrusts with the joints of its tarsus. 
This, so far as I can see, is the rather detailed and complex mechanism of the 
movement, and it is one in which each leg has its own particular purpose to 
fulfil. The legs of the left side are mainly organs of traction employed to 
pull the spider on her course. Moreover the last three serve as a series of im- 
plements to pass the radius to its anchorage on the spinnerets. The legs on 
the opposite side act chiefly as organs of support, but the hind leg 
possesses the additional function of pressing away the radii so as to extract 
the sticky line. j: 
We watch the spider. We look with wonder at all this complexity, and we 
note the precision with which each member peifforms its particular work. When 
all of a sudden the Nephila halts ; she reverses her direction ; she has been mo- 
ving to the left ; she changes, and starts on a fresh circle to the right. Now 
again observe her limbs. Those of the right side take up the duties previously 
performed by those of the left side. There is no confusion ; each assumes its 
corresponding task, and, without a sign of any hesitation, she reverses the 
functions of her limbs. Excellent ai’chitect ; she is ambidextrous in a refined 
