The Spider's modus operandi Whilst Holding Down Her Door.

Four legs (the front pairs) are, together with-the falces, used to fix on the silken underlining of the door. The falces are driven into the middle of the door, the four legs being placed so that the claws hold to the edges of the lid (fig. 12). The thick bristles on the ultimate and penultimate joints of the first two pairs of legs present a spiny array (fig. 1, female; fig. 2, male). (Fig. 3 shows a few of these terminal protective bristles, with the claws.) The remaining pairs of legs are placed around the tube, the claws sticking into the silk lining (fig. 11). All the legs are slightly bent when holding on, so that the spider's hold is elastic, and better able to withstand a jerk. When in this position the spider pulls the door tightly, often exerting a force capable of lifting a half-ounce weight.

Fig. 11 shows the profile of a spider holding her door. It will be noticed how well the spider's abdomen is protected by the curve in the side of the tube.

Sometimes whilst frantically resisting the entrance of an enemy the spider will suddenly let go the door and make as if to rush out on the intruder. If a person has his hand near when this happens he quickly drops the pin with which he has been holding the door, and removes his hand to safety. But this is apparently what the spider wishes to happen, and immediately she turns on her back again (fig. 11) and closes the door. The whole business is a ruse on the part of the spider, for she would not forsake her nest to bite any enemy.

Some spiders relinquish their hold when they perceive that they are weaker than their enemy, but they remain watching nearly hidden around the bend of the nest. Some spiders run to the bottom of their den when beaten at the door, and seek to hide themselves.

In wet weather spiders often remain at the end of their dens even when the door is touched. In captivity spiders often weave some strands