The Mississippi flathead catfish is a very good example of an animal with a rather eccentric and diverse collection of sensory abilities,by starting with a blank sheet of paper,a cat fish designer probably would not press its swim bladder into use as a kind of internal ear.The form an function of animals can only be understood in the context of their history..swim bladders would have come first,and since they were also good at amplifying vibrations in the water,they became coupled into the sensory system.Evolution is sometimes less of a watch maker than a tinkering odd job man with oily overalls and adirty face,mixing and matching as best it can to a job done by modifying the available parts.Nowhere is this convoluted and winding road more apparent than in the mechanics of one of our most treasured senses-the auditory system-and in the intricate,but to be frank rather home made apparatus involved in creating the delicate sensations of every sound we hear.