SOCIAL HABITS OK SPIDERS. 



41 



XII. 



A third type of assemblage was observed by Mr. Simon in a species of 

 Uloborus (U. republicanus), which is declared to be much more perfect, 



because it presents at the same time a common snare contributed 



8 by all the partners, and an individual snare proper to each one. 



canus. l Manv hundreds of this Uloborus live together ; they spin between 



the trees an immense web, formed of a central net quite compact, 

 upon which many individuals of the two sexes hang side by side, but these 

 assemblages are chiefly composed of males. This net is suspended by long 

 threads diverging in all directions, and attached to surrounding objects. 

 In the intervals of the open spaces formed by these large threads other 

 Ulobori hang upon their orbicular snares, in rays and circles, each one of 

 which is occupied by a single individual. One may see from time to time 

 a spider detach itself from the central group, in order to seek among the 

 upper cables a suitable place for 

 the fabrication of its orbicular 

 web. 



It is the central net that ap- 

 pears to serve as the place of 



pairing, as far as the 

 Guarding , 



Cocoons. observer was able to 

 judge by the quantity 

 of males which were there gath- 

 ered together. There, at least, it 

 is certain that the hatching of 

 the eggs takes place. This ap- 

 pears to occur almost simultane- 

 ously among all the females of 

 the same colony. At that time 

 the males have disappeared, the 

 females have ceased to spin their regular snares, and hang motionless 

 upon their central net, a few centimetres distant from each other, each one 

 guarding her cocoon. (Fig. 37.) The cocoon itself is most singular in 

 shape, and resembles more a bit of vegetable fibre accidentally fallen upon 

 the snare than the spinningwork of a spider. In its general features it 

 resembles the cocoons of our American Uloborus. (Vol. II., page 107, 

 Fig. 103.) 



The habits of this Uloborus differ little in their general characteristics 

 from those of our American species. I have elsewhere described their tend- 

 ency to hold rather closely to the neighborhood in which they were hatched, 

 so that their snares may be seen in close contiguity. Indeed, other species 

 of Orbweavers have the same tendency ; and I have observed a number 

 of small snares of young specimens spun upon the broad sheeted common 



PIG. 37. Females of Uloborus republicanus with their 

 hanging cocoons. 



