Ad ae invortance of how these forms get the radioactive materials, We know that the Plankton farms which are in close assocdation with the water have a close exchange, a good dcal of adsorption and elsorptica, following wuch nore cletely the activity donsity pattern in the river, but those animal forms which are tetting their activity mainly by their Icod have the most activity at the times of the year when thoy are feodins nost actively. During the cold periois of ths year, near hibernation, littic food boing consumed, the activity ds low, and durins ths periocs of hich physiological activity, hich food consumption, — it goss up. We notice a similar pattern, variations in this, with insect larvac who may go through a fou stages of arresting, even during the warm poricd of the year when normally the activitios would be high, and they go into arresting stage when they are not feeding and the activity wili drop off. I think Louis was referring to this. Even in some of these fish in warm temperature, if they stop taking in the material, it will go off in spite of the temperature picture, How do these things vary with distance downstrean? Of course, in through this (indicating) zone here, we have several reactors and the activity density of the organisus increases as we add nore effluent to the stroam. We find the