64 INSECT MANUFACTURES. 



to one point. This contrivance may be seen best 

 when the threads are attached to a black object. 

 Under the microscope they appear thus : 



The uses of silk in the webs 

 and nests of common spiders 

 are too obvious to be dwelt 

 on, but there is a most clever 

 and surprising adaptation of 

 the same material by several 

 foreign species of spider which 

 must be briefly stated. In the 

 Ionian islands, and also in the 

 West Indies, there are found 

 certain spiders, commonly 

 known as trap-door spiders, 

 which make a cylindrical nest 

 SPIDER'S METHOD OF in the earth, and cover the en- 



ATTACHING HER THREAD. . 



trance with a door of their own 

 construction, framed of alternate layers of silk 

 and earth, and fastened to the opening by a hinge 

 of stout silk. These spiders also line their nests 

 throughout with numerous layers of silken web 

 to the thickness of stout cartridge paper, and finish 



