230 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



IX. 



Naturalists have at various times recorded descriptions of " gregarious 

 spiders," which have attracted especial interest by their singularity. Dar- 

 win mentions a " gregarious Epeira " found in great numbers 

 Grega- ^^^^^ g^ -p^ Bajada, the capital of one of the provinces of La 

 Spiders ^'^^^- "^he spiders were large, of a black color, with ruby marks 

 Darwin. ^^^ their backs, and were all of one size, so that they " could not 

 have been a few old individuals with their families." ' The ver- 

 tical M-ebs were separated from each other by a space of about two feet, 

 but wore all attached to certain common lines of great length, that extend- 

 ed to all parts of the community. In this manner the tops of some large 

 bushes were encompassed by the united nets. These gregarious habits in 

 so typical a genus as Ei:)eira seemed to the distinguished author to " pre- 

 sent a singular case among insects which are so bloodthirsty and solitary 

 that even the sexes attack each other." In point of fact Mr. Darwin 

 had only come across a brood of Epciroids, who, for some reason of en- 

 vironment, as protection from the wind, freedom from enemies, or abun- 

 dance of food, or from sluggishness of nature, had kept within a com- 

 paratively limited space after egress from the cocoon. It is therefore 

 not allowable to .speak of this colony as a "community," in the ordinary 

 sense of the word as applied to such social insects as ants, termites, bees, 

 and wasps. 



Don Felix de Azara had the same misconcejjtion, if indeed it be one. 

 Although the family of spiders, he says, is for the most part regarded as 

 of solitary habit, there is one in Paraguay which lives in a com- 

 Spider jiiunity to the number of more than a hundred individuals, 

 nities Each spider builds a nest larger than a hat, and .suspends it aloft 

 Azara. '•'* ^^^^ canopy of a high tree or the ridge piece of a roof, in such 

 a manner as to be a little sheltered from above. From this a 

 great number of threads issue in all directions, into every available part. 

 The lines, in fact, are fifty or sixty feet long, white and thick. They are 

 traversed by other threads of great fineness, upon which arc entangled 

 winged ants and other insects, which serve as food for the connnunity of 

 spiders, each individual of which eats what itself had trapped. These spi- 

 ders all die in autumn, but leave in their nest eggs which are hatched out 

 the ensuing spring. ^^ In both the above cases the facts are undoubtedly 

 recorded correctly; but the inference from them can scarcely be justified. 



Darwin, who briefly refers to the account of Azara, appears to be (juite 

 right in thinking the Spaniard's "community" to be of the same species 

 as his own, although Walckenaer gives in a note' tiie opinion that the 



' Voyage of Heiigle, Vol. III., Zoology. 



' Voyages dans L'Ani<''rique Mcridionalo. I'ar J)ou I'clix do Azara. Toimt I'roiiiu'i 

 212, 180(i. Walckcnaci-'s Fiviiih edition. 



