As I walked and watched along the shore I saw one group of alewives, and then another, running by, looking light-colored and bright in the sunny water. Sometimes these groups seemed to be made up of one female escorted by several males, but the closer they came to shore the more intermingled they were, and it was not clear to me that this was a definite pattern. When she is running upstream, the female’s eggs are unripe, but ripen soon after arrival in the ponds, provided the water temperature is high enough--between 55 and 60 degrees may be the average spawning temperature during the big April and early May runs. As to the act of spawning, the female, depending on her size, deposits anywhere between sixty thousand and a hundred thousand eggs (each some 0.05 inches in diameter) in shallow places; and because they are sticky they adhere to gravel, sticks, stones, or whatever they settle on. The males, who have been following the females closely, immediately cover the eggs with milt, thrashing and scattering it with their tails. The eggs hatch out in some six days’ time when the water is at 60 degrees, and in three days or less at 72. When I first watched them spawn I saw a group of alewives run, circle, and weave offshore, sometimes slowing up at deeper holes on the bottom, or behind rock-protected water, and then come in close, with one quick impulse. They raced in together to the gravelly, shallow edge, through water not much more than ankle deep, with a sinewy, rippling motion. Then in the shadows under an overhanging shrub there was a flipping, whirling, and thrashing, a breaking of the surface. The female slapped up against the side of a rock with a rising, shuddering motion of the body as though it were shaking everything out of it, while the others simultaneously writhed, coiled, thrashed tails, and shimmered through. Then it seemed to me that there were a few seconds in which they slowly reassembled their senses to go elsewhere. The word “deposit” was hardly active enough. A fat pond sucker was hanging around the center of activity, following the alewives slowly like a small sunken log. It was obvious that eggs, to this crude, crass, lazy taster of a fish, were the ultimate delicacy. There were other occasions when the alewives, in greater numbers, swam next to the shore, spawning in what might have been concentric groups for several hundred yards. Some at the edge would be coiling and thrashing while others swam on or circled back. The fish that were farther out in the pond ran nervously, with eager movements, making quick turns as if reconnoitering, or practicing for a culminating turn. They collected suddenly when spawning, with quick, spontaneous decision. I noticed that the males while running in would often shoulder or press the females on. The characteristic thrashing whirl they make is sudden and amazing, almost like a pinwheel in a short burst.