XXVI. INTRODUCTION. 



benumb or paralyze the insect, which, if not at once devoured, 

 remains in a state of insonsibility, and availablo as fresh food 

 for some hours, and perhaps for several days. 



Differences between Mature and Immature Spiders. 

 A remark should bo mado on a point upon which every col- 

 lector and observer of spiders finds a difficulty almost as soon as 

 he begins to study them ; that is how it is to be known whether 

 the myriads, often, of spiders met with are adult (i.e., full- 

 grown) or not. It will be borne in mind that a spider under- 

 goes no metamorphosis at all ; neither complete, as in the case of 

 a butterfly or moth, which has arrived at maturity through the 

 well-marked stages of caterpillar and chrysalis ; nor incomplete 

 as among the Hemiptera (or bug tribes), and tho Orthoptera or 

 grasshopper group. A spider is a spider, with but very little 

 wanting of perfection in its general external appearance, from 

 the time of its exclusion from tho egg to its maturity. Maturity 

 is arrived at simply aftor several successive moultings of the 

 whole skin ; the only outward structural change that takes place 

 being at the final moult, when tho male spider attains its com- 

 plete armature of spinos, bristles, and hairs, according to its 

 kind, and the last (or digital) joints of the palpi, up to that time 

 tumid and homogeneous, break up into the digital joint properly so 

 called, and the curious, and more or less complex, congeries of 

 lobes, bulbs, and spines — palpal organs — tho use of which has been 

 before noticed ; the full dimensions of the logs are also some- 

 times not attained until the same period. The female spider, at 

 her last moult, merely dovolopes tho gonital aperture, with (in 

 those species to which thoy aro peculiar) its external processes, as 

 well as its internal structure. Up to this timo the aperture 

 is invisible, though (like the palpal organs of the male), it has 

 been gradually developing beneath tho cuticle. 



The pattern of a spider (that is the design formed by its 

 colours and markings) differs, in goneral but very little in 

 immaturity and maturity ; excepting that it is usually more dis- 

 tinct in the young, and in female examples. Still in some species 

 there ia a very striking difference betweon tho colours and mark- 



