English name: Crab

Biological classification: Animalia, Arthropoda, Crustacea, Decapoda, Reptiles.

Medical value:

Taste: salty, cold and slightly toxic. Meridian tropism: entering the liver and stomach.

Efficacy: nourishing tendons and benefiting qi, harmonizing stomach and promoting digestion, clearing heat and dredging collaterals, relieving depression and dispersing blood.

Indications: The whole crab can cure evil spirits in the chest, stagnation of blood stasis, fracture of bones and muscles, and oblique swelling. Treating postpartum abdominal pain with cooking wine and food, lochia is endless; Crab shell for treating lacquer sore.

Why do crabs walk sideways?

A. Geomagnetic field theory

Crabs rely on the geomagnetic field to judge their own direction. In the long years after the formation of the earth, the geomagnetic north and south poles reversed many times. Many creatures are at a loss and even become extinct because of the reverse transfer of the earth's magnetic poles. Crab is an ancient migratory animal. Its inner ear has a small directional magnet, which is very sensitive to geomagnetism. Due to the reversal of the geomagnetic field, the small magnet in the crab lost its original direction. In order to survive the reversal of the geomagnetic field, the crab adopts the practice of "changing with the constant", simply walking sideways without advancing or retreating.

B. biological perspective

The crab's head and chest are indistinguishable in appearance, so it is called head and chest. The feet of this animal grow on both sides of the body. The first pair of pliers are not only tools for digging holes, but also weapons for defense and attack. The other four pairs are used for walking, called walking feet. Each foot consists of seven joints, and the joints can only move up and down. The chest width of most crabs is greater than the length, so when crawling, they can only bend their feet at one side, scratch the ground with their toes, and extend their feet at the other side. When the toes reach the distant ground, they begin to contract, while the originally bent feet immediately straighten and push the body to the opposite side. Because these pairs of feet are different in length, the crab actually walks forward. However, not all crabs can only run wild. For example, monks with long wrists and crabs who live in groups on the beach can run forward. Many spider crabs that live in seaweed can also climb vertically on seaweed.

The answer to why crabs are flooding seems to provide us with an inspiration to solve some problems in life. When a person lives in the world, he will encounter many changes that are independent of human will, and the best way to adapt to these changes is to adjust himself. Otherwise, it can only cause the tragedy of "extinction" like those creatures who are not adapted to the reversal of magnetic poles. In fact, in dealing with the troubles of life, we are not going forward or backward, but walking sideways, and maybe there will be a different world. Some people may ridicule the ugly posture of crabs, but no one can deny that crabs will walk faster sideways.

C Through experiments, it is found that every limb in the crab has two bone eyes (that is, two muscles) connected, and the bending direction of the joint at the root of the limb is dorsal, so when the muscles contract, the limb moves in the dorsal direction, so the crab moves sideways.