SESSION IV 217 DONALDSON: I cringed just a little bit, Dr. Warren, when you said small in numbers, because I've made the grandiose statement that this is probably the biggest radiation experiment, numerically speaking, that's been carried out with vertebrate animals. We normally use in excess of 100,000 exposed and 100,000 controls, making 200,000 animals in each experiment, Then we have to carry another population along, so we always have reserve stocks. WARREN: But the salmon gives a small percentage of return, as you indicated. ~ DONALDSON: Yes. Even if we get only a 1 to 3 percent return, we have somewhere between 2,000 and 6,900 salmon coming back to the University pond, which is just slightly larger than this room, When you have that great a number of adult salmon—the average weight last fall was 18.6 pounds—coming to a small place like this in a twoweek interval, you have a tremendous mass of experimental material. So your statistical problems are astronomical. This return would produce at least 5 million offspring each year. To evaluate 5 million offspring, follow them step by step all through their incubation period, determine the number of anomalies, the rates of growth, individual variations between some 1,000 to [,200 lots, you need more than a computer; you need a group of trained monkey technicians, FREMONT-SMITH: help with this? How large a staff do they provide for you to DONALDSON: That was the question a group of Russian geneticists asked me last week, FREMONT-SMITH: I'm asking it now. PR aeeEa aeaun enor yasCaSee DONALDSON: Ask John. ' FREMONT-SMITH: Let's get it on the record. How large a staff? They've been supporting it for 24 years, but how large a staff do you have? WOLFE: It depends upon the season of the year. When those fish are coming back, he's got 25 or 30 students and assistants out there catching them out of the pond and going through all these ablutions -that Lauren has described. During the off-season [ don't know how many people there are.