ANIMAL BEHAVIOR, WITH EXAMPLES 



189 





In setting out to make the tube, she proceeds, with some 

 variations, in the following way: Standing on tiptoe she moves 

 her abdomen around almost in a circle between her legs, 

 touching the ground here and there 

 with the spinnerets at the end of 

 the body. The silk, pouring out, 

 catches fast in the soil, and in a 

 moment an adherent round mat, 

 three-eighths of an inch across, is 

 formed. Then she turns about, dig- 

 ging up the little silk mat entangled 

 with sand, and in a twinkhng she 

 has made it into a parcel which is 

 laid to one side. Again she spins 

 out silk over the same spot and 

 dexterously lifts up the mass with her 

 mouth parts and lays the pellet thus 

 formed beside the preceding one. By 

 such repetitions she soon temporarily 

 encircles the newly made pit with her 

 internal diggings. As the hole is 

 deepened, oftentimes she stands head 

 down in the hole and pats down the 

 new-formed opening with her abdomen. 

 Within an hour she may be down the 

 depth of her body and the hole excavated 

 sufficiently large to turn around in. Then 

 each parcel of sand, after being made and 

 brought up to the entrance, is snapped aw ay 

 from her mandibles with a sudden motion of 

 her palpi. As she progresses, she frequently 

 pauses to line the tube inside with silk, 

 or may often reinforce the surface already 

 covered to prevent the caving in of the earth. 

 When about ten inches of excavation is 

 accomplished she usually ceases her labors, 

 for the tube is now practically completed. 



The operation just witnessed is often performed in the 

 daylight, but the castle, which forms an after addition, is rarely 



The CastLe-buudmg 



Spider {Lycosa do- 



mifex) in the 



bottom of her 



burrow. 



