NEST MAKING : ITS ORIGIN AND USE. 



32'; 



surface about equal in diameter to twice the length of its body, or to 

 the spread of its legs.^ 



Thus the thick texture of the sheeted web is produced by the act of 

 beating downward ^\'ith the long spinnerets, repeated motions of which up 

 and down make little loops, which thicken over the surface and are beaten 

 down and then smoothed over by the spinnerets. (Fig. 313.) It will be 

 seen that this action does not differ from that of all other spiders while 

 engaged upon similar spinningwork. 



The spinning habit is not greatly developed among the Lycosids, al- 

 though that group of spiders furnishes some interesting examples of nest 

 making. Nevertheless, in the work of making the cocoon, in 

 mong which its spinning industry is most conspicuous, we find Lycosa 

 ' dropping into the common method of fabrication. I have ob- 

 served and described the mode of spinning a cocoon 

 which is as follows: 

 A circular cushion ,--:?^^^^i*Hi^^5^^'^^ 



Fig. 313. Tarantula putting the weft upon her rug. (Eurypelma Hentzii.) 



of beautiful white 

 silk about three- 

 fourths of an iueli 

 in diameter is the 

 piece out of whicli 

 the round egg bag 

 of Lycosa is made. 

 In spinning this 

 the spider's feet 

 clasp the circum- 

 ference of the co- 

 coon, and the body 



of the animal is slowly revolved. The abdomen is lifted up, thus drawing 

 out short loops of silk from the extended spinnerets, which, when the 

 abdomen is dropped again, contract and leave a flossy curl of silk at the 

 point of attachment. The abdomen is also swayed back and forward, the 

 filaments from the spinnefets following the motion as the spider turns, 

 and thus an even thickness of silk is laid upon the' eggs. ^ 



I have seen Saltigrades engage in the same act of spinning their co- 

 coon and silken cylindrical nest, and the words used for describing the 

 above might be almost exactly applied to the behavior of the Attoid. The 

 details of these methods of cocoon making will be reserved for the proper 

 chapter in the second volume of this work. But, in the meanwhile, this 

 reference to the method falls into the purpose of present thought. 



• See my notes on the Age and Habit.s of the .\merican Tarantula, Proceed. Acad. Nat. 

 Sci., 1887, page 377. 



= See my note on " How Lycosa Fabricates her Round Cocoon," Proceed. Acad. Nat. 

 Sci. Phila., i88-l, page 138, 



