NESTING H'A.BITS AND PROTECTIVE ARCHITECTURE. 



307 



clasp the trapline leading thereto. The occupant is sheltered beneath and 

 on both sides by the leafy walls, and, as her hammock shelters from at- 

 tacks coming from above, she may be regarded as well protected. A front 

 view of Gibberosa's nest is given at Fig. 286, and a side view at Fig. 287 ; 

 the nest is shown even more plainly at Fig. 145. 



Nesting- 

 Industry 

 Pro- 

 tective. 



V. 



The various forms of nest architecture described above may be said to 

 have developed around the instinct of protection. In other words, 

 the spinningwork of spiders used for domiciles is protective indus- 

 try. It may be well, with this in view, to make a summary of the 

 nesting habits of Orbweavers as above described, and briefly 

 compare them with those of other tribes of the order. 

 It may be said, at the outset, that the portion of the body which is 

 most assailable by enemies and least defensible by the spider is that which 



is invariably especially protected. That 

 part is the soft abdomen. Around this 

 the tube, tent, or screen, or whatever 

 characteristic defense is provided, will 





Fig. 286. Hammock nest of Gibberosa on a leaf. 



Fig. 287. Nest of Gibberosa ; side view. 



certainly be spun. It is this part that parasitic enemies assail ; it is 

 this which forms the juicy bit coveted by birds, frogs, lizards, and other 

 arachnophagous animals. The legs and even the face will therefore be 

 thrust out of the entrance of the nest or be left partially unprotected, 

 while the abdomen is entirely screened. One cannot suppose that this 

 coincidence is accidental. Evidently the animal is conscious that the ab- 

 domen is the portion of its body whicli most requires protection, and has 

 directed its industry to that end. 



The following are some of the varied forms of protective industry : 

 1. Spiders protect themselves by leafy tents, that is to say, tents, coverings, 



or screens made of bits of a leaf, of a whole leaf, or of several 

 l^ea y leaves united. The Labyrinth spider, for example, appropriates 



a dry leaf that may drop into her snare, or which she secures 

 for that purpose. It is placed in the midst of her labyrinth of crossed 

 lines, frequently with the concavity downwards. Underneath this she 

 stations herself, pressing the abdomen upward against the leaf. Insularis 

 and others of the group represented by her protective industry make a 



