. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. 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 lier tliread as she goes, until she reaches tho 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 jierpendicular according to the spider's weight
. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. 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 lier tliread as she goes, until she reaches tho 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 jierpendicular 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 sj^un 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 Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original McCook, Henry C. (Henry Christopher), 1837-1911. [Philadelphia] The Author, Academy of Natural Science of Philadelphia
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
