72 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



From some point in this first line, as d, the spider makes an attachment 

 and drops down, paying out her thread as she goes, until she reaches the 

 ground or touches the first object directly underneath her. If the air is 

 quite still and the spider large, the line will be nearly perpendicular, as d dd. 

 It will vary more or less from the perpendicular according to the spider's 

 weight and the wind's force. 



This vertical line, d dd, is lashed to the grass, foliage, or other object, 

 and then is reascended to a point, o, where an attachment is made and a 

 new line begun. This is held out in one of the hind feet quite free from the 



FIG. 67. Laying foundation lines by air currents. (First lines.) 



dropline, d dd, as the ascent is continued. The new free line (the dotted 

 line odce) is thus carried up dd and along ex to the point e, where it is 

 fastened, after having been drawn taut. This last act pulls out the line dd 

 until o reaches the point oo, and the deported (dotted) line, ode thus be- 

 comes the line, e oo. There is then completed the triangle, ed oo, within 

 which the spider at once proceeds to spin her orb. When a four sided 

 frame is spun instead of the three sided one here illustrated, precisely the 

 same method is pursued, the line eb oo being simply carried farther around 

 and down the bush until it forms the lower boundary of a trapezoid, and 

 is parallel to ecx. 



