The Need for an Internal Skeleton

The need for an internal skeleton stems largely from the nature of muscle tissue, which can exert force only by contracting and is therefore much more effective with a good lever system to work with. I belittle neither the intelligence nor the strength of the octopus; but in spite of Victor Hugo and most other writers of undersea adventure, the creature's boneless tentacles are not all that effective as handling organs. I don't mean that the octopus and his kin are helpless hunks of meat; but...