320 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



with the mothers until they gain a considerable size — a period of several 



weeks. The first, and probably the second, moult take place within the 



nest, the third occurs after the spider has commenced life on 



Domicile j^g ^^.j^ account. Although so numerous, the juvenile Ripariums 



,, in Mr. Robertson's artificial nests appeared to be on very good 



Nursery, . . ^^ . , 



terms, seldom engaging m any quarrels — not so irequenth'', he 



thought, as the same number of boys in a school would have done. The 

 mother Theridium exhibits wonderful affection for her eggs and young. 



The food of the spider is principally ants, and many deserted nests 

 were literally full of the remains of these insects. House flies, when 

 trapped upon the snares, are held very tenaciously by the viscid 

 globules which, Mr. Robertson asserts, are dispersed over the in- 

 tersecting lines. It is most interesting to watch the proceedings of the 

 juveniles when the mother is endeavoring to catch a fly. Hearing or 

 seeing a disturbance, a young spider cautiously descends a line, followed 

 at a distance by another and another. These approach the victim, evi- 

 dently as anxious to assist the mother as children are to use their little 

 fingers when they see others busy. The fly struggles in its toils, and 

 away scamper the young spiders as fast as tiny legs can carry them, re- 

 peating this process until they can make a meal ofP the fly. When an 

 insect is captured it is usually enswathed and draw^n up within the nest 

 to be devoured. 



These examples would seem to indicate that among our American The- 

 ridioids we may expect to find the nesting habit much more strongly de- 

 veloped than has heretofore been supposed. At all events, it is seen that 

 this tribe has in some of its representatives fair rivals of the Orbweavers 

 in the perfection of the nesting habit. The difference in the use, in the 

 case of Theridium, appears to be that the nests of Orbweavers are habit- 

 ually the dwelling places of their builders, while those of Lineweavers 

 are not so much permanent dwelling places as retreats for the cocooning 

 season. However, the Orbweaver's nest is also occasionally used to house 

 her cocoon. 



One may find rude examples of the nesting habit in the genus Liny- 



phia. There is no more common or more interesting snare along the 



skirts of our American woods, especially in the Middle and At- 



Nesting lantic States, than that of Linyphia marginata. This consists of 



T . , . a dome of open mesh work which is stretched in the midst of a 

 JLiinypnia. ^ 



maze of crossed lines. It looks not unlike a miniature umbrella 

 minus a handle and hung by innumerable cords to the foliage. (Fig. 157.) 

 Within this structure the spider has her abode, hanging inverted, close to 

 the ceiling, ready to dash through the flimsy fabric and seize the unfor- 

 tunate victims that drop down upon the roof through the labyrinth above. 

 Linyphia communis spins a nest precisely like the above in structure, 

 but differing from it in that the concavity of tlie dome is invariably 



