Griffith's experiment. Illustration of the experiment reported in 1928 by British bacteriologist Frederick Griffith (1879-1941), providing evidence that bacteria can transfer genetic information through a process called transformation. He infected mice with two types of pneumococcus bacteria. From left: Type II-R (rough, blue) did not kill the mice; type III-S (smooth, orange) did kill the mice; heat-killed smooth bacteria (crumpled, orange) did not kill the mice; the two non-fatal forms mixed together (rough and heat-killed smooth) killed the mice. Genetic transfer from dead to live bacteria changed the live ones to the fatal type. Labelled version: C028/8012.