Wayne Chapman., Age 20, Of Westmister If., for his question:
Haw does a spider spin from tree to tree?
Everybody loves to watch a tightrope walker perform. We hold our breath and wonder how anyone can, how anyone dares walk around so high in the air. But a little spider is a far cleverer aerial acrobat. For her size, she can trip farther and faster than any human tightrope artist in the world.
The best, the very best aerial acrobatics occur in the morning, and, in order to see the show, you must be up at dawn and outside when the grass and the shrubbery are wet with dew. The star performer is no bigger than the nail. On your little finger, so you had better take along a magnifying glass. She is a spider, and, to her, the stunning show is just a normal part of her morning duties.
She is, of course, a spinner of the finest of fine silken threads. Her spinning material is manufactured in special cells at the tail end of her fat, round abdomen. It is manufactured in liquid form and squirted out through tiny holes called spinnerets. In the air, the liquid spray quickly dries into a thread of silk.
The spider g1ues one end of her silken rope to a twig or leaf, and the rope grows longer and longer as she walks away. One end is securely fixed to a tree or shrub, and the other end is securely fixed to her body. The spider may want to spin her web across an open space in the foliage, for this is a fine place to trap a few flies.
She may have to take the first cross bars of her web across a space where there is no place for her to tread. This does not bother the busy little lady at all. She simply lets go and drops dawn, down through the air for perhaps a foot or more. Remember, she is quite safe because her silken rope is fixed to a twig at one end and to her body at the other end. The breezes awing her back and forth on her silken trapeze, and sooner or later she comes in reach of another twig. Quick as a flash, she grabs hold with her right legs and seals her rope to solid foundation.
The spider may use her line as a bridge to build a delicate orb web. She may be one of the many spiders who mere1y use their silk ropes to swing themse1ves from place to place among the branches. If so, she will walk a while through the foliage and spin herself another safety line when she wants t0 cross another open space among the foliage.
The silken rapes which the spiders use for their aerial acrobats are very strong. They are also smooth and firm, and the spider can climb back up a dangling thread or run across a rope used as a bridge. But the spiral threads used to make an orb web are of finer silk. What’s more, they are covered with sticky glue the stuff which traps the wandering fly. The spider never never puts one of her eight feet onto the sticky threads, or she would be trapped along with her victims.