A TRAPDOOR SPIDl^R. 
39 
mother spider, it maintains ’out a sinj^le liome, a tunnel in the 
ground, of its own digging, widening and deepening it as its own 
growth recpires. It will suffer from flood, famine and devastation 
rather than abandon the home of its first choice. Without a 
knowledge of its habits, the significance of various layers of silk 
upon the underside of the door of its home is not apparent. The 
la3"ers, which resemble thin, white pa])er, are closely united, but 
ma}' be separated with care. Thej^ are made one at a time, a single 
laj^er covering the entire underside of the door at the time the laj^- 
er is fabricated. Once each j-ear during the growth of the spider, 
the door, composed of earth and silk, is enlarged by adding wet 
earth to its free edge, after which a new htyer of .silk is a])plied, 
extending over the new as well as over the old part. As many as 
six or eight laj^ers nni}' be removed from an old door, but seldom 
more than that number, as the older ones disappear b}^ ])rocess of 
decaj’^. 
When the door is remov'ed, the spider makes a new one having a 
single covering. Other laja-rs are subsequently added, even in the 
case of an adult, but in the latter iiustance the succes.sive coverings 
lie wholly' one upon another, not being separated at their edges by 
earth, as the full-grown spider has no occasion to re-enlarge its 
door. 
The operation of making the door is an interesting one, and the 
entire process may be observed without inconvenience by placing 
a spider in a box of wet earth. The hinge-bearing edge of the door 
is perfectly straight upon the upper side, as is also that part of the 
tunnel’s edge to which it is joined. Against a central point on the 
straight edge of the tunnel’s rim, the spider liivst presses a small 
particle of mud. Being wet it adheres readily, which allows the 
artisan to turn about and spread over it a quantit)^ of silk, which 
makes it more secure. 'On top of this, and at either end of it, other 
particles are carefnll^’^ adjusted in like manner to the rim or to 
those in place, the operation being repeated until the structure is 
a third or a quarter of its destined width, when it is pulled over to 
a horizontal position, the spider presumably sensing an added se¬ 
curity. Further additions to its edge are made by' raising the door 
each time to a vertical position. The growing edge is circular in 
outline from the .start, and is moulded to the proper thickness be¬ 
tween the fangs and mandibles of the builder. 
No .silk is purposely' applied to the upper side, byt the under 
surface is well smeared with it, the greater part being added a lit¬ 
tle at a time as each y)article of earth is ])ut in ]dace. The word 
