The other type is represented by the web of the triangle spider. This web is most often found stretched between the twigs of a dead branch of pine or hemlock. At first sight it appears like a fragment of an orb-web (Fig. 106); but a little study will show that it is complete. The accompanying figure, by Dr. B. G. Wilder, who first described the habits of this spider ("Popular Science Monthly," 1875) illustrates the form of the web. It consists of four plain lines corresponding to the radiating lines of an orb-web, and a series of cross lines, which are spun by the cribellum and calamistrum. Each cross line is composed of two lines, about 1/500 of an inch apart. These double lines take the place of the curled threads woven by other members of the family to which the triangle spider belongs. From the point where the radiating lines meet, a strong line extends to one of the supporting twigs. Near this twig the spider rests, pulling the web tight so that there is some loose line between its legs, as shown in the enlarged figure. When an insect becomes entangled in one of the cross lines, the spider suddenly lets go the loose line so that the whole web springs forward, and the insect is entangled in other cross lines. The spider then draws the web tight and snaps it again. This may be repeated several times before the spider goes out upon the web after its prey. The triangle spider is a tiny fellow, and so closely resembles the color of the dead branch near which it rests that it is very difficult to find; its web is more easily seen, though it usually requires careful searching to discover it. THE MOTHERHOOD OF SPIDERS. [Illustration: _Fig. 107. Egg-sac of a spider._] As a rule young spiders are forced to shift for themselves, and a very hard time they have; but of this we have not space to write. With spiders, the mother's care is devoted chiefly to furnishing protection to her helpless eggs. These are placed in silken sacs, which are often very elaborate in construction and protected with great care. The most common egg-sacs are those found in the fields attached to stones and pieces of wood (Fig. 107). They are disk-shaped objects, silvery in color, and about the size of an old-fashioned three-cent piece.