I had seen them flashing and swarming inland up in the Herring Run area, but in this wide channel were new motions that needed more patience and information to be understood. For example, where the fish eddied and wheeled under the dazzling rays, I noticed one group idling in front of a submerged sand bar or reef that ran across the channel. I waited there for three-quarters of an hour before the fish showed signs of any common impulse to cross over it. One or two dashed over sportively to chase a minnow and then sped back, but the rest of them--a hundred or more--would make no move. Finally, after many circling approaches by the whole crowd, the measure of their circle came closer and closer out of the brown water to the brightly lit, coppery bar, until some of the vanguard spilled over. Then more and more sped and skittered over until the move was accomplished. Why? Were they afraid of the brightness? Did the contrast in light stop them in some way? This would hardly seem consistent with what I had found out so far. Perhaps it was just routine to their motion. Evidently alewives idle in the deeper channels where the velocity of the water is slower and easier to swim in. They respond to the relative force of the flow. Where the current is more uniformly rapid, and they are going up against it, they progress steadily. And perhaps the bar formed an eddy behind it, so that the water where they swam moved against the current in the channel and they were unable to tell their direction. The alewife hordes puzzled me as they moved slowly but definitely through the channel. A new animal, moving to unknown needs is hard to understand. You grasp for some translation between you that will not come. Relationships in the water world seem to need other senses than your own. It could be said that to understand the transition of the alewives from salt to fresh water and back you must know about the effect of the endocrine glands on the reproductive system, as well as adaptations of the kidney, along with the temperature, the time of the tides, and the chemical composition of a particular stream--just to begin with. If you are wise and devoted enough to put all the known factors together, you may come out with a unified interpretation, and be abreast of the latest theories of process. Knowledge is the motion by which the human animal may come closest to a fish. Still I looked in my ignorance for another familiarity in which we shared. Where the sea pushed inland and the alewives moved ahead or returned, I saw an indefinite route, of surpassing, complex elaboration; but in their pulse and tempo I felt something that gave me present assurance, and a touch of joy. XI Up the Valley