“…Furchtgott (1951) X-irradiated 10 rats with 200 r. and 10 with 500 r. whole-body doses and tested them in a four-unit directional water maze* His results showed no effect upon learning or retention* In another study, Furchtgott (1952) tested brightness discrimination in rats after subjecting 25 out of 50 of them to 369 r* in one case and 11 out of 23 to U69 r* in another* The m irradiated rats were slightly inferior to controls, using grey stimulus cards with Munsel values of 2,5 to 5*0 and 2*5 to 7*0 as cues with illumi nation of 0,1 foot candle at the cue. Another study by Furchtgott (1956) involved young rats (described as adolescent) which were given 300 or 500 r. and k0 days later tested for 13 days in a straight-away tank 12 feet long» The 300 r, group and control animals were essentially the same, but animals from the 500 r, group were significantly slower swimmers, Furchtgott has concluded that X-radiation near or below the median-lethal dose has little or no behavioral effect, Arnold (1952) subjected the heads of experimental rats to 300 r. and tested for retention of a previously learned llt-unit T-maze (directional).…”