208 



PROCEEDINGS OF THE ACADEMY OF 



[1888.. 



quarter tubing was built Avithin twelve hours, although of course it 

 cannot be determined how much of this time was actually consumed 

 in spinning work, probably not more than two hours. It is at least 

 evident that a length of two inches or more a day is quite within the 

 spinning capacity of Atypus, 



2. The Foundation Frame and mode of Spinning the Exterior 

 Tube. — Another specimen gave a very satisfactory clew to the entire 

 mode of constructing a tube. It first took its position at the foot 

 of the stick in the centre of the jar and wove a small lateral tube 

 extending partly around the base. (See fig. 7.) At 9 o'clock in 

 the evening this tube was pierced at the top, and the creature begao 



to erect a vertical tube along the sur- 

 face of the stick. The mode of pro- 

 ceeding was substantially as follows: 

 Single threads were attached to the 

 stick about two inches above the sur- 

 face. These threads were stretched 

 downward and over a lateral space 

 about the width of the tube to be spun, 

 extending to the little opening which 

 had been made in the tube at the base 

 of the stick. The lines were repeated 

 and over laid until at last tliey ac- 

 quired considerable consistency of tex- 

 ture. At the top terminus they were 

 attached to the stick or to one another. 

 At the bottom the point of attachment 

 was a little distance from the surface 

 of the stick so that most of the lines 

 had a slanting position. Their appear- 

 ance might be compared t(» that of 

 a number of poles leaned against a tree. The structure thus gradu- 

 ally assumed a skeleton tubular form which was increased by the 

 pressure of the spider against the lines as it moved back and forward 

 within them upon the surface of the stick. When the scaffolding 

 was completely overspun the section appeared as a close silken tube. 



3. Mode of Spinning binder ground. — A third specimen enabled 

 me to determine the manner in which this rough frame was com- 

 pleted so as to give it the close texture of the tubes found in Nature. 

 This specimen had excavated a tunnel against the inner surface of the 



Fig. 6. Purseweb Spider, 

 lines of frame for a tube. 



Foundation 



