There is a mother-principle alive in all nature that never dies. This is different from mother-love. The oak tree responds to the mother-principle, and bears acorns. It is a law of life. The mother-love or passion, on the other hand, occurs only among the higher animals. It is very common; and yet, while it is one of the strongest, most interesting, most beautiful of animal traits, it is at the same time the most individual and variable of all animal traits. This particular cow of my neighbor’s that I hear lowing, is an entirely gentle creature ordinarily, but with a calf at her side she will pitch at any one who approaches her. And there is no other cow in the herd that mourns so long after her calf. The mother in her is stronger, more enduring, than in any of the other nineteen cows in the barn. My own cow hardly mourns at all when her calf is taken away. She might be an oak tree losing its acorns, or a crab losing her hatching eggs, so far as any show of love is concerned. The female crab attaches her eggs to her swimmerets and carries them about with her for their protection as the most devoted of mothers; yet she is no more conscious of them, and feels no more for them, than the frond of a cinnamon fern feels for its spores. She is a mother, without the love of the mother. In the spider, however, just one step up the animal scale from the crab, you find the mother-love or passion. Crossing a field the other day, I came upon a large female spider of the hunter family, carrying a round white sack of eggs, half the size of a cherry, attached to her spinnerets. Plucking a long stem of grass, I detached the sack of eggs without bursting it. Instantly the mother turned and sprang at the grass-stem, fighting and biting until she got to the sack, which she seized in her strong jaws and made off with as fast as her long, rapid legs would carry her. I laid the stem across her back and again took the sack away. She came on for it, fighting more fiercely than before. Once more she seized it; once more I forced it from her jaws, while she sprang at the grass-stem and tried to tear it to pieces. She must have been fighting for two minutes when, by a regrettable move on my part, one of her legs was injured. She did not falter in her fight. On she rushed for the sack as fast as I pulled it away. She would have fought for that sack, I believe, until she had not one of her eight legs to stand on, had I been cruel enough to compel her. It did not come to this, for suddenly the sack burst, and out poured, to my amazement, a myriad of tiny brown spiderlings. Before I could think what to do that mother spider had rushed among them and caused them to swarm upon her, covering her, many deep, even to the outer joints of her long legs. I did not disturb her again, but stood by and watched her slowly move off with her encrusting family to a place of safety.