FOOD OF INSECTS. 239 



them are so various, that it is impossible to enumerate more than a few of 

 the most remarkable. Agelene labynnthica extends over the blades of grass 

 a large white horizontal net, having at its margin a cylindrical cell, in the 

 bottom of which, secure from birds and defended from the ra\ 7 s of the sun, 

 the spider lies concealed, whence, on the slightest movement of her net, 

 she rushes out upon her prey. Aranea latens F. conceals itself under a 

 small net spun upon the upper surface of a leaf, and thence seizes upon any 

 insect that chances to pass over it. Theridium 13-guttatum forms under 

 stones and in slight furrows in the ground a net consisting of threads spun 

 without any regularity in all directions, but so strong as to entrap grass- 

 hoppers, which are said to be its principal food ; and a similar inartificial 

 snare of simple threads is often spun in windows by Theridium bipunctatum 

 and several other species. Segestria senoculata and its affinities conceal 

 themselves in a long cylindrical straight silken tube, from the mouth of 

 which they stretch out their six anterior feet, whose extremities rest upon 

 as many diverging threads : thus, as soon as an insect walks across any of 

 the threads (which are eight or ten inches long) the insect's toes give it 

 warning of prey being at hand, when it rushes out and seldom fails to 

 secure its victim. 



" The spider's touch, how exquisitely fine ! 

 Feels at each thread, and lives along the line." 



M. Homberg tells us that he has seen a vigorous wasp carried off and 

 destroyed by one of these species. 



The spiders to which I have hitherto adverted seize their prey by means 

 of webs or nets ; but a very large number, though, like the former, they 

 spin silken cocoons for containing their eggs, and often line their cells and 

 places of retreat with silk, never employ the same material in constructing 

 similar snares, of which they make no use. 



These may be separated into two grand divisions : the first comprising 

 those which conceal themselves and lie in ambuscade for their prey, and 

 sometimes run after it a short distance ; the second, those which are con- 

 stantly roaming about in every direction in search of it, and seize it by open 

 violence. The former Walckenaer, in his admirable work on spiders, has 

 designated by the name of Vagrants, the latter by that of Hunters ; term- 

 ing those already mentioned which spin webs and nets, Sedentaries : if to 

 these you add the Swimmers, or those species which catch their prey in 

 the water, you will have an idea of the general manners of the whole race 

 of spiders. 1 



The artifices of that tribe which Walckenaer has named vagrants are 

 various and singular. Several species conceal themselves in a little cell 

 formed of the rolled up leaf of a plant, and thence dart upon any insect 

 which chances to pass ; while others select for their place of ambush a hole 

 in a wall, or lurk behind a stone, or in the bark of a tree. Aranea calydna 

 L. more ingeniously places herself at the bottom of the calyx of a dead 

 flower, and pounces upon the unwary flies that come in search of honey; 

 and A. arundinacea buries herself in the thick panicle of a reed, and seizes 

 the luckless visitors enticed to rest upon her silvery concealment. Many 



1 Some slight alterations in M. Walckenaer's original divisions, but which need 

 not be here particularised, have been made in his later works on spiders. 



