THE ARMATURE OF ORP.WEBS : VISPID SPIRALS. 93 



ningwork at the point where it was abandoned and finished it in the usnal 

 manner, so that the orb })resented the appearance shown at Fig. 87. The 

 s})irals were not only greatly deltated by the action of the rain, the crossed 

 lines being merged and twisted together at the middle part, but the beads 

 upon them had been taken up by the raindrops, a number united into one, 

 so that instead of the ordinary condition of a vast number of minute beads 

 spread entirely along the line there appeared a nnich smaller 



Interrupt- j^^^j^-^l^gj. q£ |3cads of larger size, that distinctly showed to the 

 ed Bead- 



• -p- naked eye. Then the vniexplained mystery of the Orchard spider's 



ished. peculiar snare flashed upon my mind ! At once the mystery 

 was solved, and that in a most simple and natural way. The 

 peculiar appearance of the orb was simply the result of the spiders resum- 

 ing arrested work upon the spirals after the same had been abandoned on 

 account of a shower, and which in the meantime had been twisted and 

 deltated by the action of the elements, and the size and grouping of the 

 beads clianged. As the renewed work was spun in, in the ordinary way, 

 both as to the position of the lines and the size of the beads, the con- 

 trast with the larger beads and the more widelj'^ separated spirals of the 

 earlier belt was very great. It was not the first time that I learned the 

 valuable lesson that natural phenomena are often to be explained by the 

 simplest and ordinary causes, while we are vainly speculating and philoso- 

 phizing over some supposed occult and mysterious reason. 



ITT. 



Mr. Blackwall remarks that "the estimate of the number of viscid 

 globules distributed on an elastic spiral line in a net of E})eira apoclisa of 

 a medium size will convey some idea of the elaborate operations 

 f^ T ^*^ ^^^^ Epeiroida3 in the construction of their snares." ^ This quo- 

 tation evidently indicates that Blackwall sui)posed the viscid glob- 

 ules to be the result of " elaborate operations" on the i)art of the Orbweaver, in 

 other words, that they are formed by direct and intentional action. This 

 lias l)e('n tlie well nigh universal belief. Bui in the light of the 



^ ^ , true mode above recorded, it is necessary to diminish by so much 



Corrected , _ , „ , ' ^ i • i •, i p t i 



the credit heretorore bestowed upon this child oi Arachne. 



It would be an extremely laborious, if not impossible task, to ascertain 



the exact number of beads upon an orbweb, but I reached a near enough 



approximation by the following i)rocess: A sector of a snare was taken, that 



is, a complete section extending from the hub to the circumference between two 



radii, and the number of beads thereon was carefully counted. 



• ^^ ^j' This sector was then measured and the su])erficial area calculated. 

 ingBeads. . . , ^ , • ^ ^ t ^ ■ ^ -, ■ ^ 



ihe sui>erficial area or the entire beaded sj^ace having been obtained 



in like maniici', the number (if beads ujioii the whole web was readily calcu- 

 1 .Trtnr. T.inn. Soc, 1829, Vol. XYT., pajro 477, and Ann. Mur. Nat. Hist., Vol. XV., i\ijre 239. 



