Spiders 



slightly funnel-shaped mouth of the burrow ; at one side 

 a strong silken hinge completes the lid. 



When the young trapdoor-spider first builds its under- 

 ground home it covers the external opening with a thin, 

 wafer-like layer of silk and soil. As it grows it enlarges 

 its burrow and at the same time increases the dimensions 

 of its lid by adding alternate layers of silk and soil. The 

 upper surface of the lid it always covers with the material 

 of the immediate neighbourhood, be it shingle or moss, 

 sand or grass, so that detection of its haunt may be 

 rendered difficult. All the work of digging is performed 

 by the spider's mouth ; particle by particle the soil 

 fragments are taken up in the spider's mouth and re- 

 moved to a distance. Everything in order, the spider 

 awaits its prey at the door of its residence. Having made 

 a capture, it retires to its inmost recesses to enjoy its meal, 

 secure in the knowledge that few will discover its well- 

 concealed home. But the spider is not without its enemies, 

 who, having discovered the spider residence, try to open 

 the door. The inmate resents this intrusion, and by 

 clinging to the silken lining of the lid with its jaws and 

 fore-feet and to the silken lining of the burrow with its 

 other feet, it is often able to save the situation. Should 

 the door be forced, the spider slides down the smooth 

 lining of his home with astonishing rapidity. 



Some of the trapdoor-spiders construct a more com- 

 plicated burrow, making it in the form of the letter Y. 

 The lower arm of the Y is, of course, permanently closed ; 

 one of the upper arms is provided with a trapdoor ; the 

 other upper arm is closed with a wafer-like layer of silk, 

 skilfully concealed on the outside with moss or grass. 

 This arm of the nest forms an emergency exit should 

 the occasion arise for a rapid retreat. Another more 

 ingenious Y-shaped nest-builder constructs a fragile trap- 

 door at the junction of the arms of its haunt. When the 

 upper door, the real trapdoor, is forced this spider beats 

 a hasty retreat to the lower cul-de-sac of its home and 

 s 273 



