The Effect of Thermal Neutron Radiation on the Chromosomes of Datura.

pattern by making it difficult to delimit sectors clearly. Although the data at hand precluded the possibility of making rigorous comparisons between plants arising from seed subjected to thermal neutrons and plants from x-irradiated seed, no developmental or morphological disturbances or lethality patterns in Datura unique to either kind of treatment were detected. Caldecott, Frolik, and Morris4 found that individual barley seed subjected to identical doses of x-rays were variously affected, as determined by seedling heights, but injury was much more uniform with identical doses of thermal neutrons. These investigators also reported that "differential" delayed killing was characteristic in barley exposed to 10,000 to 20,000 r units of x-radiation, but that similar lethality patterns'did not occur in thermal neutron-treated material. Further study of thermal neutron induced pollen lethals in Datura is in progress.