Part 13

The trap-door sooner or later wears out at the hinge, and is then discarded and a new door manufactured. We saw many nests with the old door lying near the entrance. The door is made of several layers of silk and clay, and is a substantial affair.

The spider families all have the gift of genius. Of what ingenious devices and arts are they masters! How wide their range! They spin, they delve, they jump, they fly. They are the original spinners. They have probably been on their job since carboniferous times, many millions of years before man took up the art. And they can spin a thread so fine that science makes the astonishing statement that it would take four millions of them to make a thread the caliber of one of the hairs of our head--a degree of delicacy to which man can never hope to attain.

Trap-doors usually mean surprises and stratagems, secrets and betrayals, and this species of the arachnids is proficient in all these things.

The adobe soil on the Pacific coast is as well fitted to the purposes of this spider as if it had been made for her special use. But, as in all such cases, the soil was not made for her, but she is adapted to it. It is radically unlike any soil on the Atlantic coast--the soil for cañons and the rectangular watercourses, and for the trap-door spider. It is a tough, fine-grained homogeneous soil, and when dry does not crumble or disintegrate; the cohesion of particles is such that sun-dried brick are easily made from it.

This spider is found in New Mexico, Arizona, California, and Jamaica. It belongs to the family of Mygalidae. It resembles in appearance the tarantula of Europe, described by Fabre, and has many of the same habits; but its habitation is a much more ingenious and artistic piece of workmanship than that of its European relative. The tarantula has no door to her burrow, but instead she builds about the entrance a kind of breastwork an inch high and nearly two inches in diameter, and from this fortress sallies out upon her prey. She sinks a deeper shaft than does our spider, but excavates it in the same way with similar tools, her fangs, and lines it with silk from her own body.

Our spider is an artist, evidently the master builder and architect of her kind. Considering her soft and pussy-like appearance--no visible drills for such rough work--one wonders how she excavates a burrow six inches or more deep in this hard adobe soil of the Pacific coast, and how she removes the dirt after she has loosened it. But she has been surprised at her work; her tools are her two fangs, the same weapons with which she seizes and dispatches her prey, and the rake or the cheliceræ. To use these delicate instruments in such coarse work, says Fabre, seems as "illogical as it would to dig a pit with a surgeon's scalpel." And she carries the soil out in her mandibles, a minute pellet at a time, and drops it here and there at some distance from her nest. Her dooryard is never littered with it. It takes her one hour to dig a hole the size of half an English walnut, and to remove the earth.

One afternoon I cut off the doors from two nests and left them turned over, a few inches away. The next morning I found that the occupants of the nests, under cover of the darkness, had each started the construction of a new door, and had it about half finished. It seemed as if the soil on the hinge side had begun to grow, and had put out a semicircular bit of its surface toward the opposite side of the orifice, each new door copying exactly the color of the ground that surrounded it, one gray from dead vegetable matter, the other a light brick-red. I read somewhere of an experimenter who found a nest on a mossy bit of ground protectively colored in this way. He removed the lid and made the soil bare about. The spider made a new lid and covered it with moss like the old one, and her art had the opposite effect to what it had in the first case. This is typical of the working of the insect mind. It seems to know everything, and yet to know nothing, as we use the term "know."

On the second morning, one of the doors had attained its normal size, but not yet its normal thickness and strength. It was much more artfully concealed than the old one had been. The builder had so completely covered it with small dry twigs about the size of an ordinary pin, and had so woven these into it, standing a few of them on end, that my eye was baffled. I knew to an inch where to look for the door, and yet it seemed to have vanished. By feeling the ground over with a small stick I found a yielding place which proved to be the new unfinished door. Day after day the door grew heavier and stronger. The builder worked at it on the under side, adding new layers of silk. There is always a layer of the soil worked into the door to give it weight and strength.

Spiders, like reptiles, can go months without food. The young, according to Fabre, go seven months without eating. They do not grow, but they are very active; they expend energy without any apparent means of keeping up the supply. How do they do it? They absorb it directly from the sun, Fabre thinks, which means that here is an animal between which and the organic world the vegetable chlorophyl plays no part, but which can take at first-hand, from the sun, the energy of life. If this is true, and it seems to be so, it is most extraordinary.

In view of the sex of the extraordinary spider I have been considering, it is interesting to remember that one difference between the insect world and the world of animal life to which we belong, which Maeterlinck has forgotten to point out, is this:

In the vertebrate world, the male rules; the female plays a secondary part. In the insect world the reverse is true. Here the female is supreme and often eats up the male after she has been fertilized by him. Motherhood is the primary fact, fatherhood the secondary. It is the female mosquito that torments the world. It is the female spider that spins the web and traps the flies. Size, craft, and power go with the female. The female spider eats up the male after he has served her purpose; her caresses mean death. The female scorpion devours the male in the same way. Among our wild bees it is the queen alone that survives the winter and carries on the race. The big noisy blow-flies on the window-pane are females. With the honey bees the males are big and loud, but are without any authority, and are almost as literally destroyed by the female as is the male spider. The queen bee does not eat her mate, but she disembowels him. The work of the hive is done by the neuters. In the vertebrate world it is chiefly among birds of prey that the female is the larger and bolder; the care of the young devolves largely upon her. Yes, there is another exception: Among the fishes, the females are, as a rule, larger than the males; the immense number of eggs which they carry brings this about.

There are always exceptions to this dominance of the female in the insect world. We cannot corner Nature and keep her cornered. She would not be Nature if we could. With the fireflies, it is the male that dominates; the female is a little soft, wingless worm on the ground, always in the larval state.

In the plant world, also, the male as a rule is dominant. Behold the showy catkins of the chestnuts, the butternuts, the hazelnuts, the willows, and other trees. The stamens of most flowers are numerous and conspicuous. Our Indian corn carries its panicle of pollen high above the silken tresses which mother the future ear.

One day I dug up a nest which was occupied by a spider with her brood of young ones. I took up a large block of earth weighing ten pounds or more, and sank it in a box of earth of its own kind. I kept it in the house under observation for a week, hoping that at some hour of day or night the spider would come out. But she made no sign. My ingenious friend arranged the same mechanical contrivance over the door which he had used successfully before. But the latch was never lifted. Madam Spider sulked or bemoaned her fate at the bottom of her den. At the end of a week I broke open the nest and found her alone. She had evidently devoured all her little ones.

I kept two nests with a spider in each in the house for a week, and in neither case did the occupant ever leave its nest.

Apparently the young spiders begin to dig nests of their own when they are about half-grown. As to where they stay, or how they live up to that time, I have no clue. The young we found in several nests were very small, not more than an eighth of an inch long. Of the size and appearance of the male spider, and where he keeps himself, I could get no clue.

One morning I went with my guide down to the spider territory, and saw him try to entice or force a spider out of her den. The morning previous he had beguiled several of them to come up to the opening by thrusting a straw down the burrow and teasing them with it till in self-defense they seized it with their fangs and hung on to it till he drew them to the surface. But this morning the trick would not work. Not one spider would keep her hold. But with a piece of wire bent at the end in the shape of a hook, he finally lifted one out upon the ground. How bright and clean and untouched she looked! Her limbs and a part of the thorax were as black as jet and shone as if they had just been polished. No lady in her parlor could have been freer from any touch of soil or earth-stain than was she. On the ground, in the strong sunlight, she seemed to be lost. We turned her around and tried to induce her to enter the nest again; but over and over she ran across the open door without heeding it. In the novel situation in which she suddenly found herself, all her wits deserted her, and not till I took her between my thumb and finger and thrust her abdomen into the hole, did she come to herself. The touch of that silk-lined tube caused the proper reaction, and she backed quickly into it and disappeared.

Just what natural enemy the trap-door spider has I do not know. I never saw a nest that had been broken into or in any way disturbed, except those which we had disturbed in our observations.

IV. THE DESERT NOTE

I often wonder what mood of Nature this world of cacti which we run against in the great Southwest expresses. Certainly something savage and merciless. To stab and stab again suits her humor. How well she tempers her daggers and bayonets! How hard and smooth and sharp they are! How they contrast with the thick, succulent stalks and leaves which bear them! It is a desert mood; heat and drought appear to be the exciting causes. The scarcity of water seems to stimulate Nature to store up water in vegetable tissues, just as it stimulates men to build great dams and reservoirs. These giant cacti are reservoirs of water. But why spines and prickles and cruel bayonets? They certainly cannot be for protection or defense; the grass and other vegetation upon which the grazing animals feed are not armed with spines.

If the cacti were created that grazing animals in the desert might have something to feed upon, as our fathers' way of looking at things might lead us to believe, why was that benevolent plan frustrated by the armor of needles and spines?

Nature reaches her hungry and thirsty creatures this broad, mittened hand like a cruel joke. It smites like a serpent and stings like a scorpion. The strange, many-colored, fascinating desert! Beware! Agonies are one of her garments.

All we can say about it is that Nature has her prickly side which drought and heat aggravate. In the North our thistles and thorns and spines are a milder expression of this mood. The spines on the blackberry-bush tend against its propagation for the same reason. Among our wild gooseberries, there are smooth and prickly varieties, and one succeeds about as well as the other. Apple-and pear-trees in rough or barren places that have a severe struggle for life, often develop sharp, thorny branches. It is a struggle of some kind which begets something like ill-temper in vegetation--heat and drought in the desert, and browsing animals and poor soil in the temperate zones. The devil's club in Alaska is one mass of spines; why, I know not. It must just be original sin. Our raspberries have prickles on their stalks, but the large, purple-flowering variety is smooth-stemmed.

Mr. John C. Van Dyke in his work on the desert expresses the belief that thorns and spines are given to the desert plants for protection; and that if no animal were there that would eat them, they would not have these defenses. But I believe if there had never been a browsing animal in the desert the cacti would have had their thorns just the same.

Nature certainly arms her animal forms against one another. We know the quills of the porcupine are for defense, and that the skunk carries a weapon that its enemies dread, but I do not believe that any plant form is armed against any creature whose proper food it might become. Cacti carry formidable weapons in the shape of spines and thorns, but the desert conditions where they are found, heat and aridity, are no doubt their primary cause. The conditions are fierce and the living forms are fierce.

We cannot be dogmatic about Nature. From our point of view she often seems partial and inconsistent. But I would just as soon think that Nature made the adobe soil in the arid regions that the human dwellers there might have material at hand with which to construct a shelter, as that she gives spines and daggers to any of the vegetable forms to secure their safety. One may confute Mr. Van Dyke out of his own mouth. He says:

Remove the danger which threatened the extinction of a family, and immediately Nature removes the defensive armor. On the desert, for instance, the yucca has a thorn like a point of steel. Follow it from the desert to the high tropical table-lands of Mexico where there is plenty of soil and moisture, plenty of chance for yuccas to thrive, and you will find it turned into a tree and the thorn merely a dull blade-ending. Follow the sahuaro and the pitahaya into the tropics again, and with their cousin, the organ cactus, you will find them growing a soft thorn that would hardly penetrate clothing.

But are they not just as much exposed to browsing animals in the high table-lands as in the desert, if not more so?