A fish’s spinal cord weighs about the same as the fish’s brain. In a human the brain weighs about 55 times as much as the spinal cord. Various species of monkeys range from eight to 18 to one. Cats are four to one.

A fish’s spinal cord weighs about the same as the fish’s brain. In a human the brain weighs about 55 times as much as the spinal cord. Various species of monkeys range from eight to 18 to one. Cats are four to one.