82 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



Fn;. 81. Movements of the body while spin- 

 ning spirals. 



circumference of the orb grasp the radius as it is approached. This 

 describes in a general way the method of locomotion. In other words, 

 the legs towards the circumference reach forward toward the approached 



radius. At the immediate instant when 

 the spinnerets clamp the new made string 

 upon the radius the whole body is at rest 

 and is balanced by the legs in the posi- 

 tion just described (Fig. 79), that is, on 

 the upper side supported by the two fore 

 legs ; on the forward side (towards the 

 head of the spider) by the other 

 two fore and third legs, holding 



am nig ^ ^ radius ; and on the lower 

 Clamped. 



side by the hind foot, which 



also grasps the radius just below the point 

 of intersection. Of course, this period of 

 poise, as a rule, is so brief that it is 

 scarcely noticeable. At times, however, 

 when the spider appears to be moving more sluggishly, for one reason or 

 another, the moment is sufficiently prolonged to permit the observation. 

 I have often seen that the spider would make a quite noticeable pause 

 before the hind foot let go the new spiral string, permitting it to snap into 

 its position between the two radii. Sometimes the position of the spider 

 will differ from the above in detail; for example, when the beaded strings 

 have been brought up close to the scaffold line, 

 they can be fastened while the spider hangs 

 with her sides nearly parallel with the scaffold. 

 In such case the legs on one side will hold on 

 to the scaffold, while at least two legs on the 

 under side remain free, and grope about with 

 the restless motion of feeling after something, 

 heretofore described. In these operations the 

 scaffold line is generally well bent downward 

 instead of being taut as shown in the cuts. 



The general line of progress of the Orb- 

 weaver's body while spinning the spirals is il- 

 lustrated at Fig. 81, where R represents the 

 radii, SF, SFx, SFy are spiral scaffold lines, 

 and SP true beaded spirals. The spider en- -^' 

 gaged upon the spiral A fastens it to the FIG. 82. Dropping action on the down- 

 radius 1R at the point of contact; then the 



course of the body is upward along 1R to the spiral foundation SFx ; 

 thence across the section B thereof; thence downward along radius 2R, 

 until at the point C opposite A she can tighten and fasten the line 



