SPIDERS AND THEIR WEBS 
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malmignatte are about the only species in the United States that will 
harm any one by their bite. 
An interesting group are the orb-weavers. These make webs that 
are circular or partly circular in form, consisting of radii and circular 
spirals like the spokes and rims of a wheel. Sometimes these webs 
lie flat, but more often they hang vertically. The spiral lines are the 
elastic ones, and are usually sticky in order that they may trap and 
hold their prey. If they were not elastic, they would break when the 
insect begins to struggle for freedom. Examine a web and notice 
the difference between the support lines and these elastic spiral 
threads. 
The line-weavers build webs somewhat similar to those of the orb- 
weavers, but instead of the spiral lines theirs are simply a network of 
interlaced lines. We see these in the comers of rooms, in barns, and 
on shrubbery. Usually you will find the spider hanging from the center 
of the web. Often he will drop by means of his silken thread several 
feet below the web and there wait for his prey. The moment the web 
is touched he feels the tremble through his supporting thread and 
hastens to his dinner. Often he simply hides behind a leaf at some dis¬ 
tance from the web, but always carries his warning thread with him. 
The spider has his spinnerets on the extremity of his abdomen, and 
it is from them that he spins his web. 
The tube-weavers make a tubular or cone-shaped nest with a wide- 
spreading net over the top or spreading out from the top. These are 
often to be found in hedges and fence-rows. 
The trap-door spider is a sort of tube-weaver. He burrows be¬ 
neath the ground and spins his silken net inside of the hole. The taran¬ 
tula is of this sort also, but he does not make a trap-door. He relies 
upon his venomous bite to protect himself from invaders; while the 
trap-door spider, being harmless and timid, makes himself a trap-door 
The tube of the trap-door spider is first lined with a papery sub- 
stance similar to a hornet’s nest, then the silk comes inside this. Some¬ 
times he builds the trap with one edge thicker than the other so that it 
shuts by its own weight. But most commonly it is of an even thickness 
and hung on silken hinges that stretch when it is opened- and shut with 
a snan when he goes in or out. Sometimes this spider builds a second 
tube unSeath or to one side of the first, with a trap-door. Then 
