44 ARACHNOIDEA. 



CASE in corners and out of the way holes, but a large proportion by 

 forming the webs for which the family is best known. Their vora- 

 city is extreme, and the numbers they consume are consequently 

 very great ; a quality, however, which is sometimes directed against 

 themselves, for they make no exception in their search for food, 

 often devouring one another, the weaker falling a prey to the 

 stronger ; and as the females are, with few exceptions, larger and 

 stronger than the males, a courtship among the spiders is a service 

 by no means unattended with danger. Like other carnivorous 

 animals whose prey is precarious, and like the venomous snake, 

 which hes in wait for its prey, and must often have a long and 

 weary vigil before it comes, the spider, although so voracious, is 

 capable of long abstinence from food. Mr. Blackwall notices the 

 case of a female Theridion quadri-punctatum, which still survived 

 after being eighteen months without food corked up in a phial, a 

 period exceeding the usual natural duration of most spiders' lives, 

 which is said to be about twelve months ; some, however, have a 

 longer time, individuals having been known to live four years. 



All spiders at present known have either two, six, or eight 

 smooth eyes, which vary much in size and relative position, 

 supplying characters which have been much used in the sys- 

 tematic arrangement of species. The falces or modified mandibles 

 or jaws with which the spider seizes its prey are inserted immedi- 

 ately under the anterior margin of the cephalo-thorax, and have 

 usually at the extremity of their inner surface a longitudinal groove, 

 provided with sharp teeth on the sides, which receives the fang 

 when in a state of repose. The fang, or last joint of the falcis, is 

 very hard, curved, acute, and has a small fissure near the point, 

 which emits a colourless, more or less venomous, fluid secreted 

 by a gland. 



The palpi occupy the same place and relations as in other 

 insects, but they are distinguished by those of the male being 

 swollen at the extremity into a curiously twisted, variously formed 

 organ. Those of the females remain simple. In most other 



