236 EVENmGS AT THE inCEOSCOPE. 



"We will not then toucli the moral question ; but 

 just look at this apparatus from the head of one of our 

 common Spiders {Cluhiona atrox)^ a long-legged and 

 swift species, that builds a compact cloth-like web in 

 our out-houses, with a gallery open at each end for re- 

 treat in danger. Tlie specimen is a part of the slough 

 or cast skin, which you may always find in the neigh- 

 bourhood of such a web ; and it is particularly suitable 

 for examination, because it is sloughed in the most per- 

 fect condition ; every part, the fangs, the palps, the 

 legs with all their joints, the corneje of the eyes, the 

 entire skin with every hair, — all are here, and all in 

 situ, with a cleanness and translucency which it would 

 require much skill in dissection to obtain, if we cap- 

 tured a living Spider for our purpose. 



There are in front of the head two stout brown or- 

 gans, w'hich are the representatives of the antennse in 

 insects ; though very much modified both in form and 

 function. They are here the eftective weapons of 

 attack. Each consists of two joints : the basal one, 

 which forms the most conspicuous portion of the organ, 

 and the terminal one, which is the fang. The former 

 is a thick hollow case, somewhat cylindrical, but flat- 

 tened sidewise, formed of stift' chitine, covered with mi- 

 nute transverse ridges on its whole surface, like the 

 marks left on the sand by the rippling wavelets, and 

 studded with stout coarse black hair. Its extremity is 

 cut off" obliquely, and forms a furrow, the edges of 

 which are beset with polished conical points resembling 

 teeth. 



To the upper end of this farrowed case is fixed by a 

 hinge-joint the fang, which is a curved claw-like organ, 

 formed of hard chitine, and consisting of two parts, a 



