National Geographic : 1933 Aug
186 THE NATIONAL GEOGRAPHIC MAGAZINE Photograph by W. B . Johnstone THE SIERRA DOME SPIDER SETS ITS SNARE FOR INSECTS IN FLIGHT Every species has its own design peculiarly adapted to its needs. Linyphia litigiosa spins this inverted bowl; its cousin, Linyphia communis, makes a similar trap right side up (see text, pages 163, 187). Photograph by Lynwood M. Chace FROM SETS OF SPINNERETS THE SPIDER CONJURES HER SILK Each of the fingerlike organs (greatly magnified in the photograph) can turn out a thread. Frequently there are not five but six in each group; the one showing white at the right is a fusion of two.