Mrs. Spider Spins Her Web
BEAUTY is in the eye of the beholder, it is said. That can well be stated of Mrs. Spider.
Usually when she happens to come in contact with one of those giants of the earth—Man or Woman—she is greeted with kicks, brooms and flying objects. Her workmanship, one of the marvels of the “world of small things,” is termed a cobweb and brushed aside.
Of course, some humans do speak of the beauty of a dew-covered spider web at dawn. And some do know that Mrs. Spider is normally mankind’s friend, helping to control the insect population and generally striving to stay out of man’s way.
But if more persons knew of her architectural ability, might not even more change their minds? Despite her eight hairy legs and matronly figure, might they not see the beauty of her artistry? Consider just a few of the designs by some of these lady architects.
Web Designs
At first glance many spider webs would appear to be little more than a jumble of thin threads. But further examination will often reveal great ingenuity.
For example, Mrs. Platform Spider (it is always Mrs., as males do not spin webs) strings many “guy wires” in a crisscross pattern. Below these she constructs a tightly woven silk sheet. Flying insects hit the “wiring” and fall into the net below.
Others build a bow-shaped sheet; and yet others, a rounded dome under which the spider hides. Captured insects are pulled through these sheets. Then Mrs. Spider—often a very tidy housekeeper—repairs her silky “tablecloth.”
But not all webs are motionless traps. One spider actually fashions a lasso. This small, elastic web is pulled taut between the twigs of an evergreen tree and held in place by the “cowgirl” until some unsuspecting mosquito bumps into it. Flash! She lets out some slack on her line and the web springs forward, entangling the intruder! With a series of such snapping movements, the mosquito is thoroughly corralled.
While not all varieties of spiders construct webs, such designers are numerous among the more than 29,000 known kinds. And yet, amidst them all, one “family” is considered distinctive, the artists par excellence. They are the orb (or round) web weavers. These, according to one authority, “build the most beautiful and complicated of all webs.”
Would you like to watch an orb weaver and see how she does it? Let us observe Aranea, the “queen of the spider architects,” as she vigorously begins her next project.
Aranea Spins Her Web
First of all, you will have to watch closely, for she moves quickly and decisively. Her first accomplishment must be the securing of a main line or “bridge line” from which to work out the foundation lines of her web.
You may wonder at her choice of location—right over a small stream! Why not pick an easier place? But apparently she knows the value of setting her net over an “insect air-line.”
How will she get a line across the stream? See her perched on that twig and raising her belly into the air? She is casting out a silk thread, which the breeze will lift like a kite as she continues to “play out string.” Holding the string by the claw of one leg, she feels when it hits something on the other side of the brook. Her objective reached, she pulls up the slack in the line and so has her tightrope over the water.
Working from this bridge line, how rapidly she lays out the foundation lines, forming a rectangle (other supports will later stretch this into a many-sided pattern)! Now note how she goes to the center of the top line of this rectangle and, attaching a silk thread, drops through the air to the middle of the bottom line.
With the rectangle thus halved, she goes to the center of this dividing line and attaches another thread. ‘How does she find center without a measuring tape?’ you may ask. A very good question, but no one has discovered the answer!
In any case, from this midpoint Aranea carefully plays out her line and walks up to the top foundation line. Traveling along this line a short distance from its center point, she stops and attaches the new rope. (See Diagram No. 1.) The first “spoke” of a geometric wheel has been formed.
For each spoke she will return to the center point or hub and play out a line by walking along the newly laid webbing. Observe that this little engineer puts one spoke on the right-hand side and then the next on the left—alternating to keep the strain balanced until all the spokes are in! All twenty-five (or more) are marvelously equidistant, when one considers the speed and working conditions.
After strengthening the center with a few spiral lines, Mrs. Spider now seems to lose interest. Starting from near center, she lays down a rough, wide-spaced spiral across the spokes. Sloppy workmanship? No, for this spiral is simply “scaffolding”—a platform from which to do the more difficult finish work. Aranea will dismantle this scaffolding as each section of it is no longer needed.
Now, starting from a point near the edge of the rectangle, she works in a spiral toward the center. For this circular webbing she has switched to an elastic, glue-coated silk. For years this sticky webbing has amazed naturalists. Why so? Because each segment had beads of glue exactly equidistant from one another.
How could this tiny creature measure these out so precisely? Then, finally, the secret came out. After Mrs. Spider has laid her glue-smeared line between two spokes, she plucks or “twangs” it like a violin string. The vibration separates the glue into equidistant drops!
So Aranea moves slowly from spoke to spoke in concentric circles, tying, gluing and twanging some 13,000 of these short sticky lines. Finally, after a few finishing touches, she is ready for the last step: installing “telephone” service.
She now runs a silky “telephone line” from her web to her hideaway—often under a nearby leaf. As Aranea cannot see very well, she depends a great deal on her excellent sense of touch. When an insect flies into the web and gets stuck there, the thrashing sends vibrations down the “telephone line,” informing Mrs. Spider that her “grocery store” has just been stocked.
In fact, since these vibrations signal mealtime, when Mr. Spider comes to court, he wisely drums a little “tune” on the edge of the web. This “serenade” prevents him from being pounced on by his nearsighted lover!
In considering the engineering and craftsmanship of Aranea, you may find it difficult to believe that less than one hour was needed for the entire operation. Can you imagine any man being able to spread out and mount a net over a wide river in one hour—manufacturing his own rope, glue and “telephone” system at the same time?
Even more astounding is that Aranea will not bother to make repairs when insects tear her netting. She will take the whole web out of its framework and make a new one! Ordinarily she does this once every twenty-four hours. How can she keep doing this? Where does all that silk come from?
Her “Spinning Equipment”
While all spiders have silk glands or “factories,” some have more than others. Of the possible seven different types, most spiders will have from three to five kinds. Each produces a different silk. But how does Mrs. Spider control and work these silks?
Well, underneath her abdomen there are usually six tubelike organs called spinnerets. It is from these that the several different silks are ejected. However, it is not as if she simply has six movable hoses.
Each spinneret is a small lump composed of more than a hundred tiny tubes—each tube able to be individually controlled! Commenting on the threads produced by this intricate “equipment,” one naturalist says: “The spider’s spinning machine is far superior to that devised by man to spin bridge cables, for the spider can vary the size and strength of its cable at will merely by spreading the [spinnerets] apart or placing them closely together.”
The “Intelligence” Dilemma
‘Amazing,’ declares the scientist who studies her anatomy. But, if he is a proponent of evolution, Mrs. Spider also presents him with a serious dilemma.
How did this tiny animal (she is not an insect, which only has six legs to the spider’s eight) “discover” and “evolve” oil glands in her “feet,” preventing her from sticking to her own glue? Who taught her engineering and geometry?
‘Instinct,’ one may say. True, the ability to make webs is instinctive, for many baby spiders make “perfect miniatures no larger than a postage stamp.” But we still face the dilemma of how such a small creature “evolved” such a wide range of instructions.
‘Well, she evolved them over the centuries,’ the evolutionist replies. But as one of them honestly notes: “There are no scientific grounds for supposing that the habits of spiders generally have greatly changed.” So with each discovery about her, the question resurfaces: Why does she display an “intelligence” not found in much larger, so-called “more advanced” creatures?
For other persons there is no dilemma. They accept the concise answer found in the Bible at Genesis 1:25: “And God proceeded to make . . . every moving animal of the ground according to its kind.”
Thus, in the final analysis, you have a decision to make. When you next see the gauzy web of Mrs. Spider, ask yourself: What Master Architect taught her to weave?
[Diagram on page 21]
(For fully formatted text, see publication)
SPINNING AN ORB WEB
bridge line
foundation lines
first spoke
center line
(1) Foundation lines hang from bridge line
(2) “Spokes” constructed (simplified)
(3) Completed web (simplified)